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8/19/2014 7:46 P.M. ET

Ubaldo moved to bullpen; Gonzalez will start Sunday

CHICAGO -- The Orioles have moved struggling starter Ubaldo Jimenez to the bullpen, manager Buck Showalter announced on Tuesday.

Signed this winter to a four-year, $50 million deal -- the largest contact in club history for a free-agent pitcher -- Jimenez has dealt with injury and ineffectiveness, and he gave up six earned runs over 4 1/3 innings in Cleveland last weekend.

After that game, Showalter wouldn't commit to whether Jimenez -- 4-9 with a 4.83 ERA -- would get a chance to redeem himself, though the move to the bullpen seemed likely, particularly with right-hander Miguel Gonzalez, who will return from the Minor Leagues to start on Sunday, waiting in the wings.

"You got your reasons, he doesn't have to agree with them," Showater said of Jimenez, with whom he spoke on Tuesday afternoon, along with pitching coach Dave Wallace and bullpen coach Dom Chiti. "He's been a great teammate, a professional. Has got a good heart. He wants to do well. It's not like he's pitched poorly all year, it's just with 39 games left, [we want to] see how Gonzo does."

Gonzalez has a 3.80 ERA in 20 games (19 starts), and he threw a simulated game on Monday to stay on track.

The move won't be immediate with Jimenez taking his work day on Tuesday, but Showalter plans to use him in relief after that.

"After today [Jimenez] will probably be available in the bullpen," Showalter said. "We will see where it takes us moving forward -- where the need might be, if somebody needs an extra day or something. The target is trying to get though to [roster expansion] on Sept. 1. So we've got about less than two weeks."

How Jimenez will be used out of the bullpen depends on how the Orioles clear a roster spot for Gonzalez on Sunday. If they play with a short bench, it would be tough to see Jimenez getting a lot of outs, although if the O's option a pitcher, he would presumably take his place.

Jimenez has made just one career relief appearance, throwing one scoreless inning on Sept. 26, 2006. How will he fare in this role?

"I don't think anybody can sit here and answer that," Showalter said. "I know he will embrace that as the need of the club it is. A lot of it depends on if we go with 13 pitchers or 12. How that all works out. He's healthy, feels good. One of the reasons why we looked at [him], he was one of the few guys that health wasn't going to be -- knock on wood -- a factor.

"Hopefully, we can get him back to where he was last year. It's going to be tough, because he's not going to sit there and take a lot of work days, because it's a very valuable job he's going to have to do now and then."

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