The Orioles have placed infielder Wilson Betemit on the 15-day disabled list after an MRI taken before Thursday's game showed a small cartilage tear in his right wrist and a deep bone bruise.

First baseman Joe Mahoney was called up from Triple-A Norfolk to replace Betemit on the roster.

Betemit hadn't played in a game since Saturday. Before the call-up of rookie Manny Machado last week, Betemit had become the team's everyday third baseman.

The switch-hitting Betemit has been one of the club's best hitters against right-handed pitching, batting .306 from the left side of the plate. With Machado up, he had been relegated to a platoon role at first base with Mark Reynolds, who is hitting only .196 against right-handed pitching but .266 against left-handers.

Betemit will report to Sarasota, Fla., on Friday morning, but he will be shut down for the next week to give the injury time to heal. He will be eligible to come off the disabled list Aug. 27, and manager Buck Showalter said he is optimistic Betemit will be ready by then.

Mahoney flew in from Norfolk before Thursday's game. This is his second stint with the big league club, after a five-day call up in July right before the All-Star break. He went 0-for-3 in the one game he appeared in, July 7 against the Los Angeles Angels.

The 25-year old won the Orioles' 2010 Brooks Robinson Minor League Player of the Year Award when he hit .319/.378/.545 for Double-A Bowie. This season, he has posted a .263/.317/.390 for the Tides.

Johnson's role

Showalter said right-hander Steve Johnson was a candidate to start Saturday's game in Detroit, as long as the Orioles didn't need to use the St. Paul's alum in long relief Thursday.

But Johnson pitched the eighth and ninth innings — throwing 28 pitches — leaving in question who will make that start.

“There's still that potential he can pitch there,” Showalter said after the game. “He hadn't pitched in seven days. We didn't want to pitch anyone else. We were down to our last guy. I was trying to stay away from Steve if I could.”

Johnson, 24, hadn't pitched in a game since his first major league win Aug. 8, shuttling to and from Norfolk in that span and missing a scheduled start with the Tides when he was called back up.

His schedule has been less than consistent, but Johnson was confident he'd do fine no matter how he was used.

“I've been through that this whole season, so whether it's going back to the bullpen or a spot start or whatever it is, I'm ready for it,” Johnson said before the game. “I haven't pitched in a while, so really it's not too hard. I'm going to pitch in the next few days, I know that whether it's today, tomorrow or the next day, so I'm ready for either one.”

If the Orioles need to call up a pitcher from the minors to make Saturday's start, it could mean the end of Mahoney's stint with the big league club.

Reimold update

Showalter said he spoke to outfielder Nolan Reimold Thursday, and the injured outfielder is doing well in his rehab from a neck surgery. The Orioles' Opening Day left fielder has been out since the end of April.

Reimold has completed four weeks of an eight-week rehab, Showalter said, but he is still not far along enough to know his availability for potential postseason play.

Around the horn

Right-hander Jason Hammel threw off a mound Thursday for the second time since surgery on his right knee in mid-July, and the session didn't go as well as the first one did. Hammel's knee is fine, but his arm is a little more "cranky" than it was the day after his first session, Showalter said. … Right-hander Branden Kline, a Frederick native taken by the Orioles in the second round of this year's draft, made his professional debut for short-season Single-A Aberdeen on Thursday night. He pitched three innings and gave up three earned runs on four hits with five strikeouts and one walk. … Steve Tolleson returned from the disabled list Thursday at Norfolk and started at shortstop, going 1-for-4 with a two-run single and three strikeouts.

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