Here’s what happened down in the Orioles’ farm system on Thursday…

* Zach Britton struggled through 4 2/3 innings, but Jonathan Schoop hit a home run to help Triple-A Norfolk to a 7-3 win over Buffalo

* Eddie Bamboa was roughed up for four runs in six innings as Double-A Bowie dropping a 5-1 final to Erie

* Jerome Pena, Zane Chavez, and Steve Bumbry each drove in two despite Single-A Frederick’s 12-9 loss to Winston-Salem

* Matt Taylor allowed only two earned runs in 5 1/3 innings despite Single-A Delmarva falling 3-1 to Hagerstown

(Updated: 12:00 a.m.)

BALTIMORE — Wanting to play it safe with the nasty blister that’s developed on starter Miguel Gonzalez’s right thumb, the Orioles have elected to place the right-handed pitcher on the 15-day disabled list.

The club has recalled right-handed reliever Alex Burnett from Triple-A Norfolk to take his place on the 25-man roster as well as provide an extra arm in the bullpen for the next couple nights. Gonzalez’s DL stint is retroactive to May 4, meaning the 28-year-old could return to the starting rotation as early as May 19 in a series finale against the Tampa Bay Rays.

Gonzalez completed a bullpen session on Thursday with a bandage covering the thumb, but he only threw fastballs as the blister that developed under a broken callous hindered his ability to throw his two-seam fastball and off-speed pitches. According to manager Buck Showalter, the plan is for Gonzalez to complete another bullpen session this weekend in Minnesota and then throw a rehab start at either Bowie or Norfolk next week.

Of course, a blister is a very tricky ailment for a pitcher that you can’t rush in fear of re-aggravating the skin and putting yourself right back in the same predicament. The Orioles remain confident that the decision to place Gonzalez on the DL is the proactive choice that will eliminate the problem for the remainder of the season.

“I just think this is the most prudent thing to do,” Showalter said. “I don’t care what happened today; he’s still going to be tentative throwing his breaking ball and his split. If it forms again, you’re going to have a season-long problem, so we just decided to get that done before he had the work day and get that out of his mind.

On the surface, the short-term loss of Gonzalez would create a problem after the Orioles finally appeared to ease their fifth-starter dilemma — at least for the time being — with veteran Freddy Garcia. The good news is the Orioles will only be faced with the problem of replacing Gonzalez in the rotation for Saturday’s start since they benefit from days off next week on Monday and Thursday.

Showalter was initially tight-lipped regarding his thoughts for Saturday’s starter, but announced that right-hander Steve Johnson would be recalled to take the ball in Minnesota. The 25-year-old Johnson pitched for Triple-A Norfolk on Monday, throwing 94 pitches, allowing two earned runs, and striking out eight in 5 2/3 innings against Buffalo.

Once they’ve completed Saturday’s game, the Orioles could get away with using only Wei-Yin Chen, Jason Hammel, and Chris Tillman as starters all the way through Sunday, May 19 when Gonzalez would hypothetically be ready. Of course, that means Garcia would be available to pitch in relief or make a start should they want to give any of the aforementioned pitchers such as Chen an extra day of rest as Showalter often likes to do when able.

As Showalter likes to say, there are plenty of moving parts and a lot could change quickly, but the Orioles appear to be in good shape to endure Gonzalez’s absence thanks to a couple well-placed days off after recently completing a 20-day stretch void of any scheduled days of rest.

Roberts surgery successful

Second baseman Brian Roberts underwent right hamstring surgery on Thursday morning in Dallas in what was deemed a successful procedure.

The 35-year-old exchanged some text messages with Showalter and is expected to return to Sarasota this weekend where he’ll begin a six-week recovery period. The hope is that the procedure will eliminate any tangible risk of re-injuring the hamstring once Roberts is able to resume baseball activity.

“Everything went well today,” Showalter said. “Very positive. The doctors felt good about getting it done after getting in there. It will speed up the process. I’ve got marked off what [six] weeks is from today, so we’ll see what happens.”

Showalter expressed empathy for Roberts’ latest setback while acknowledging some of the frustration and emotional responses expressed by critics and fans regarding the $10 million the second baseman is making this season in the final year of a four-year, $40 million contract.

Various injuries have limited Roberts to just 118 games over the last four seasons.

“He’s not going to give in,” Showalter said. “That’s why it makes me confident that he’ll come back and be a contributor. We think he’s worth waiting on. It’s been tough on him. It would be kind of selfish to say it’s tough on us. It’s tougher on him if you put yourself in the position he’s been in the last two or three years and ask yourself sincerely what you would do.”

Orioles add minor-league third baseman Wood

Executive vice president of baseball operations Dan Duquette sent cash considerations to the Kansas City Royals in exchange for infielder Brandon Wood on Thursday.

The 28-year-old will report to Triple-A Norfolk as he continues to plug away in a disappointing career that once held a tremendous amount of promise. Wood was Baseball America’s No. 3 prospect in all of baseball prior to the 2006 season but has never been able to put it together at the big-league level.

In 700 career at-bats in the major leagues, Wood has a career .186 average with 18 home runs, 64 RBIs, and 218 strikeouts.

Back in 2006 and 2007 when the Orioles were exploring trades for shortstop Miguel Tejada, the Angels were often linked in discussions with Wood’s name mentioned as a player the club might covet in return. He became somewhat of a folk hero in the minor leagues by hitting 43 home runs and 53 doubles in his 2005 season split between high Single A and Triple A.

However, the talent that once made scouts salivate never came to fruition at the big-league level as the Orioles will now be Wood’s fifth different organization.

Odds & ends

Closer Jim Johnson picked up his 85th career save on Wednesday night. If he collects 21 more this season, he will move into second place on the club’s all-time list ahead of Tippy Martinez (105) and Stu Miller (100). Gregg Olson remains the Orioles’ all-time saves leader with 160. … Left fielder Nate McLouth has stolen 11 bases (second in the American League) and is on pace to steal 52 this season. That would be the third-best mark in Orioles history behind Luis Aparicio (57 in 1964) and Brady Anderson (53 in 1992). … The Orioles have the highest team fielding percentage (.991) in baseball in the 85 games since third baseman Manny Machado arrived in Baltimore on Aug. 9, 2012. … Since July 29, 2012, the Orioles have the best record in baseball at 62-33 (.652 winning percentage) as well as the best home record at 32-13 (.711 winning percentage).

Here’s what happened down in the Orioles’ farm system on Wednesday…

* Jair Jurrjens pitched six solid innings and Danny Valencia homered in Triple-A Norfolk’s 8-4 win over Buffalo

* Double-A Bowie’s game against Richmond was postponed due to rain

* Steve Bumbry homered and Jerome Pena and Zane Chavez each drove in two despite Single-A Frederick falling to Winston-Salem in a 12-9 final

* Single-A Delmarva was off on Wednesday

BALTIMORE — The news wasn’t encouraging for Orioles second baseman Brian Roberts after seeking a second opinion on his right hamstring as he’ll undergo surgery and will be sidelined at least six more weeks.

Roberts visited knee specialist Dr. Daniel Cooper in Dallas on Wednesday morning as it was determined the 35-year-old would undergo a “semitendinosus release” procedure on Thursday. Roberts will eventually report to Sarasota to begin rehabilitation in hopes of making his return this summer.

Earlier this week, Roberts was taking light batting practice before complaining that the back of his right knee didn’t feel right, which prompted the infielder to see Dr. Cooper. He is the same doctor who cared for Rays third baseman Evan Longoria’s injured hamstring last year.

“If you look at all the scenarios and the way it’s transpired, this is the best chance for him to get back and not have an issue with it again,” said manager Buck Showalter, who added that Dr. Cooper was the specialist who handled his recent knee surgery. “A lot of experts think this can get you back and not have it reoccur again because it keeps the scar tissue from forming, which creates other issues. Full support of it and hopefully he’ll make the time period and be able to pick up where he left off and not have that in the back of his mind. I know what his goals are.”

Roberts has played in only three games this season as the original prognosis for a return was three to four weeks after he injured his knee sliding into second base on April 4 at Tropicana Field. The club has officially labeled the injury a right hamstring strain, but Roberts actually tore the tendon behind his knee.

This procedure will hopefully facilitate quicker healing for the veteran infielder, who has played in only 118 games over the last four seasons while dealing with various ailments. It is all but a certainty that Roberts will be transferred to the 60-day disabled list once a need arises to make a 40-man roster move.

“He’s very frustrated by it, as we are, but Brian Roberts is going to come back and make a contribution to this club this year,” Showalter said. “I’ve got a good feeling about that.”

The starting second baseman was sent to the 15-day DL on April 5 and has been replaced by a platoon of Ryan Flaherty and Alexi Casilla.

The hamstring procedure will mark the third time in the last year Roberts has undergone surgery after dealing with a torn labrum in his hip last season and a sports hernia in the offseason. The longtime Oriole is in the final year of a four-year contract that is paying him $10 million this season.

Markakis serves as DH again

Never one to miss much playing time before a 2012 campaign marred by two freak injuries, right fielder Nick Markakis served as the designated hitter for the third time this season on Wednesday night.

You can imagine the stoic Markakis isn’t thrilled about serving in a limited capacity, but the 29-year-old expressed appreciation to Showalter, acknowledging that it will help keep him fresh over the course of a 162-game schedule. The Gold Glove right fielder served as the club’s DH only four times combined from 2010 through 2012.

“It’s different,” Markakis said. “You just have to stay loose, stay stretched and wait for your turn to hit. Haven’t done it too much, but it’s good. It gives me time off and a chance to get my feet back under me. It’s a different mindset, but it’s good every once in a while.”

Showalter told Markakis he would see more time in the role this season and the right fielder denied there was any physical challenge that’s limiting his time in the field. Little-used reserve Chris Dickerson started in right field in the second game of a three-game set with Kansas City.

Observers have noted that Markakis’ throwing arm hasn’t looked as strong this season, which could be a product of wear and tear as well as long-term effects of serving as a power pitcher in college. Upon selecting Markakis with the seventh overall pick of the 2003 draft, many talent evaluators suggested the Orioles should make Markakis a pitcher at the professional level after he played in the outfield and pitched for Young Harris College.

“It’s tough to go out there and play every day, especially for a long time over years,” Markakis said. “This is good every once in a while. There is a lot of running in the outfield. To not have to worry about defense and just focus on offense, it gives you mentally a break as well as physically.”

Guesswork with Gonzalez

Right-handed pitcher Miguel Gonzalez will throw a bullpen session on Thursday to test out the healing blister on his right thumb and determine whether he can make Saturday’s start in Minnesota.

Both Gonzalez and Showalter have admitted there will be a certain amount of guesswork in determine whether he will take the hill against the Twins or whether he will be skipped in favor of someone else. He will throw with a bandage covering the area to protect it while going through his workday, but Showalter acknowledged they won’t fully know whether he’s OK until he’s pitching without the added protection.

Gonzalez feels confident that his four-seam fastball won’t be an issue, but he expressed some hesitation whether his two-seam and off-speed grips will impact the healing area.

Depending on how the next few games go, Showalter could elect to make Saturday a bullpen day should Gonzalez need additional time before his next start or the club could dip to Triple-A Norfolk where Steve Johnson would be pitching on normal rest on Saturday.

The club will receive a break with the rotation headaches next week as Monday and Thursday are scheduled days off and will allow Showalter to reset his bullpen in a way he’d like while managing Gonzalez’s blister even more if necessary.

Betemit progressing slowly

Veteran switch-hitter Wilson Betemit continues to make progress in recovering from a Grade 2/3 PCL tear but hasn’t been cleared for baseball-related activities.

The 31-year-old is eligible to return from the 60-day DL at the end of the month, but Showalter acknowledged that would likely be a stretch at this point.

The Orioles would benefit from Betemit’s bat in the lineup against right-handed pitching as their DH position is hitting just .145 with three home runs and nine RBIs this season.

Here’s what happened down in the Orioles’ farm system on Tuesday…

* Jake Arrieta allowed four earned runs in 6 2/3 innings as Triple-A Norfolk dropped a 6-4 final to Buffalo

* Double-A Bowie’s game with Richmond was postponed due to rain

* Single-A Frederick’s game at Winston-Salem was postponed due to rain

* Single-A Delmarva’s game with Charleston was postponed due to rain

BALTIMORE — Taking light batting practice in Sarasota was supposed to be an important step in the return of Orioles second baseman Brian Roberts, but it instead created more uncertainty regarding his status moving forward.

Complaining that the back of his knee didn’t feel right as he attempted to take swings, the 35-year-old infielder will see knee specialist Dr. Daniel Cooper in Dallas to get a second opinion on his recovery from a torn tendon suffered behind his right knee. Dr. Cooper is the same specialist who cared for Tampa Bay Rays third baseman Evan Longoria when the All-Star infielder suffered a hamstring injury last season.

“He started taking some batting practice and just didn’t like the way it felt,” said manager Buck Showalter, who supported Roberts’ request for a second opinion. “He said he wasn’t expecting that with the progression that we’ve done, and I think he’s just a little frustrated that it hasn’t come faster.”

The original prognosis for a return was three to four weeks after Roberts injured his knee sliding into second base on April 4 at Tropicana Field. The club has officially labeled the injury a right hamstring strain, but Roberts actually tore the tendon behind his knee.

In Roberts’ absence, the club has used a second-base platoon of Ryan Flaherty and Alexi Casilla that’s provided little offensive production as Flaherty is hitting just .125 and Casilla is sitting at .200. After previously hesitating to place Roberts on the 60-day disabled list, which would officially keep him off the big-league roster until early June, it now appears the Orioles wouldn’t hesitate to make the move should a roster need arise elsewhere.

The new development also makes you wonder if executive vice president of baseball operations Dan Duquette will look more carefully outside the organization for help at second base, but Showalter is publicly remaining optimistic until Dr. Cooper provides answers that might suggest otherwise in regards to Roberts being a likely candidate for the 60-day DL.

“No more than he was before,” Showalter said. “I’m not looking at it that way. I’m still holding out hope that this will get going. I like the fact that we don’t have a need for it yet.”

Wait-and-see mode with Gonzalez

The Orioles won’t know when right-handed pitcher Miguel Gonzalez will make his next start until he completes his bullpen day on Thursday to determine how well the blister on his right thumb has healed.

Gonzalez will cover the area with a bandage during his workday, but the pitcher isn’t allowed to wear as much as a Band-Aid on his finger when throwing in a game. The earlier Gonzalez would be ready to pitch is likely Saturday with his bullpen day falling on the final day of the Kansas City series.

Showalter isn’t ruling out the possibility of Gonzalez being skipped in the rotation entirely if the blister continues to be an issue.

“It’s getting better,” Showalter said. “It’s a blister underneath a callous. It’s kind of good in a way that it broke, tore off — whatever you want to say — so we’ve gotten all the way down to the bottom. Now, it’s a matter of getting [it] calloused over.”

Thursday would have been Gonzalez’s normal turn in the starting rotation, but veteran Freddy Garcia will instead take the hill against former Orioles Jeremy Guthrie in the series finale against the Royals.

Odds & ends

Shortstop J.J. Hardy received an injection in his right elbow from Dr. Lewis Yocum in Anaheim over the weekend for a case of mild tennis elbow, according to Showalter. It is not considered a big deal. … Starter Jason Hammel picked up his fifth win on Sunday to begin the year 5-1. According to Elias, with a win in his next decision, Hammel will become the first Orioles pitcher to go 6-1 or better to start consecutive seasons since Mike Boddicker, who started 6-1 in 1985 and 10-1 in 1986. … The Orioles have made just one error in the last 10 games and three in the last 17 games. … The Orioles (0-for-9) and Royals (1-for-10) are batting a combined .053 as pinch-hitters. … Baltimore has eight players with three or more home runs, the most for any American League team. Cleveland and Oakland are tied for second with six each. The Chicago Cubs lead the majors with nine players having three or more homers.

Here’s what happened down in the Orioles’ farm system on Monday…

* Steve Johnson struck out eight in 5 2/3 innings as Triple-A Norfolk won 8-3 over Buffalo

* Henry Urrutia drove in three runs despite Double-A Bowie falling in a 6-3 final to Richmond

* Eduardo Rodriguez allowed three earned runs in six innings as Single-A Frederick defeated Winston-Salem in a 10-3 final

* Parker Bridwell was roughed up for four runs in five innings of work as Single-A Delmarva dropped a 10-4 final to Charleston

Less than a week after making his major league debut with the Orioles, right-handed pitcher Zach Clark finds himself at a career crossroads after being designated for assignment and clearing waivers.

Unable to crack a crowded starting rotation at Norfolk that includes Jake Arrieta, Zach Britton, Jair Jurrjens, Steve Johnson, and Josh Stinson, the 29-year-old Clark will instead be outrighted to Double-A Bowie where he will begin focusing on throwing a knuckleball in competitive games.

In his only appearance with the Orioles, Clark allowed three earned runs in 1 2/3 innings of work in Seattle. The UMBC product was removed from the 40-man roster over the weekend to make room for veteran right-hander Freddy Garcia.

Organization pitchers Eddie Gamboa and Zach Staniewicz worked on the knuckler with Hall of Fame pitcher Phil Niekro this spring, so executive vice president of baseball operations Dan Duquette and manager Buck Showalter have clearly embraced the idea of hurlers using the novelty pitch. Showalter was influential in getting 2012 National League Cy Young Award winner R.A. Dickey to begin focusing on the knuckleball when they were together in Texas.

In eight seasons of minor league baseball, Clark is 50-46 with a 3.71 earned run average.

Here’s what happened down in the Orioles’ farm system on Sunday…

* Travis Ishikawa and Luis Exposito each drove in three runs as Triple-A Norfolk beat Syracuse in a 6-5 final in 11 innings

* Kevin Gausman allowed just two earned runs in seven innings, but Double-A Bowie fell in a 2-1 final at Akron

* Zach Davies picked up the win despite allowing five earned runs in 5 2/3 innings for Single-A Frederick in a 6-5 win over Carolina

* Former first-round pick Matt Hobgood pitched 4 1/3 scoreless innings in relief to help Single-A Delmarva beat Charleston in a 5-2 final

After Josh Stinson and Zach Britton failed in their recent bids to secure the Orioles’ fifth starter spot, veteran right-hander Freddy Garcia is the next up for an opportunity Saturday in Anaheim.

As expected, the Orioles selected the contract of the 15-year veteran to make Saturday’s start against the Los Angeles Angels and designated right-handed pitcher Zach Clark for assignment to make room on the 25-man and 40-man rosters. The Orioles had recalled Clark to provide an extra arm in their overworked bullpen after Britton was ineffective in Monday’s start in Seattle and was optioned to Triple-A Norfolk.

Signed to a minor-league deal only days before the start of the season, Garcia has made five starts for the Tides and sports a 4-0 record with a 2.67 earned run average spanning 33 2/3 innings. He has struck out 21 and walked only two while surrendering 31 hits over those starts.

He will wear No. 38.

After learning earlier this week that Garcia had agreed to extend his opt-out clause from five minor-league starts to May 14, it became clear the Orioles were seriously considering the two-time All-Star pitcher for a promotion. Garcia has completed eight innings in each of his last starts and pitched on Sunday, allowing two earned runs and striking out five in a win over Toledo.

Garcia spent the last two seasons with the New York Yankees, making 42 starts and going 19-14 with a 4.29 ERA over that time. However, the native Venezuelan struggled in the Bronx last season with a 5.20 ERA and was sent to the bullpen at two different points. He didn’t pitch in the postseason for the Yankees.

In his career, Garcia has spent time with Seattle (1999-2004), the Chicago White Sox (2004-2006 and 2009-2010), Philadelphia (2007), Detroit (2008), and the Yankees (2011-12). His 152 career victories rank ninth among active pitchers, and he has the most wins for any Venezuelan-born pitcher in baseball history. He has gone 6-3 with a 3.28 ERA in 10 career postseason starts, including seven shutout innings in clinching Game 4 of the 2005 World Series for the White Sox.

It remains to be seen whether Garcia’s impressive numbers at Norfolk will translate to major league success, so the Orioles hope he can provide much-needed innings on Saturday as they wrap up an 11-game West Coast trip. It’s unknown whether the club will provide the right-hander a longer leash than provided to Stinson or Britton, but the club will continue to monitor what’s happening at Triple A.

Should Garcia falter, right-handers Steve Johnson and Jair Jurrjens would figure to be the next pitchers deserving of an opportunity for the spot originally held by Jake Arrieta at the start of the season. Johnson was activated from the 15-day disabled list earlier this week after making two rehab starts while Jurrjens has a 3-1 record with a 2.56 ERA in six starts for the Tides. Jurrjens has his own opt-out clause that allows him to become a free agent should he not be in Baltimore by June 15.

The club could also look to Rule 5 selection T.J. McFarland, who has pitched well out of the bullpen in a long-relief role so far this season.

Clark, a UMBC product, appeared in one game for the Orioles, making his major league debut in Seattle on Wednesday. The 29-year-old allowed three earned runs in 1 2/3 innings and would figure to have a good chance of passing through waivers and being outrighted to Norfolk.

In other roster news, catcher Luis Exposito has cleared waivers and been outrighted to Triple A.