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04/17/12 8:33 PM ET

Minor Leaguer Ohlman suspended 50 games

CHICAGO -- Minor League catcher Michael Ohlman has received a 50-game suspension after a second violation of the Minor League Drug Prevention and Treatment Program for a drug of abuse, Major League Baseball announced on Tuesday.

The suspension of Ohlman, who was on the disabled list of the Class A Delmarva Shorebirds, will be effective immediately. He is the second catcher in the organization to be suspended for violating the program, with Brian Ward serving a 50-game suspension that started at the beginning of the season.

Ohlman, 21, was drafted by the Orioles in the 11th round of the 2009 First-Year Player Draft out of Lakewood Ranch (Fla.) High School, and spent the 2011 season with Delmarva. His right shoulder was injured in a car accident this spring, and he is expected to miss substantial time because of the injury.

Arrieta continues productive start to season

CHICAGO -- Lost in the shuffle of Monday's 10-4, 10-inning Orioles win was the performance of starter Jake Arrieta, who received a no-decision but turned in his third straight solid outing, tying a career high with 114 pitches.

Arrieta took the hill in the sixth with 65 pitches and only one run allowed, White Sox catcher A.J. Pierzynski's solo homer, but the Orioles defense committed three errors behind him, leading to a pair of unearned runs. The 26-year-old Arrieta struck out seven and was charged with four runs (two earned) on seven hits and a walk.

"There was an eight- or nine-inning outing there last night for him, just couldn't secure the baseball behind us some and elongated some innings," manager Buck Showalter said on Tuesday afternoon. "[Arrieta has] been solid. I think his command is the first thing that you see that he's better with the repair work done to his elbow. You can tell he's freer about attacking the strike zone and knowing where the fastball is going. Because it all works off the fastball."

Arrieta, who was shut down last August and had a bone spur removed from his right elbow, was a full-go this spring and earned the Orioles' Opening Day nod, his second consecutive season pitching the home opener. In his first three starts, Arrieta is 1-0 with a 2.66 ERA, allowing only six earned runs on 14 hits and four walks over 20 1/3 innings. Arrieta has also struck out 16.

O's claim catcher Exposito off waivers

CHICAGO -- The Orioles announced on Tuesday afternoon that they have claimed catcher Luis Exposito off waivers from the Red Sox.

Exposito, 25, is a career .268/.324/.420 hitter over seven Minor League seasons in Boston's system. He was the club's 31st-round selection in the 2005 First-Year Player Draft.

To make room for Exposito on the 40-man roster, the Orioles designated infielder Josh Bell for assignment. The 25-year-old switch-hitter, currently at Triple-A Norfolk, batted .200/.221/.264 in 79 games with the Orioles in 2010 and '11. He was acquired on July 30, 2009, in exchange for left-hander George Sherrill.

The move will give the Orioles organizational depth, as they were thin at the catching position behind starter Matt Wieters. Ronny Paulino, who arrived at camp three weeks late, made the club as the backup with Taylor Teagarden on the disabled list.

"He' a catcher, we are a little thin there," manager Buck Showalter said of Exposito. "I'm not sure exactly where they are going to send him or what the plan is, but we got some good reports on him. He's a good addition to once again strengthen our 40-man roster. That's something we didn't have."

Brittany Ghiroli is a reporter for MLB.com. Read her blog, Britt's Bird Watch, and follow her on Twitter @britt_ghiroli. This story was not subject to the approval of Major League Baseball or its clubs.