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4/10/2013 7:58 P.M. ET

Strained right biceps lands Lackey on disabled list

BOSTON -- After a couple of days of deliberation, the Red Sox decided that the best course of action was to place righty John Lackey on the disabled list, retroactive to Sunday.

The good news is that the injury -- diagnosed as a strained right biceps -- is still not believed to be serious.

Alfredo Aceves will take Lackey's spot in the rotation and pitch Thursday night against the Orioles. Felix Doubront, who was originally slated to take that turn, will instead go Friday night against the Rays.

"We wanted another right-hander in this ballpark against Baltimore," said manager John Farrell. "Alfredo has had some good performance numbers against some individuals in their lineup, particularly [Matt] Wieters. Keeping him from the left side of the plate was probably -- well, it was one of the factors in that."

A couple of days ago, the Red Sox thought there was at least a chance Lackey could just miss one start and avoid a trip to the DL.

"He went through some light throwing and the biceps still had some stiffness to it," said Farrell. "Not knowing how many days he'll have to have that irritation completely resolved, we just felt like it was in his best interest to put him on the DL, let that recover at its own rate and not he feel like he's up against the calendar and forcing things to get back to the mound. Again, his health and well being is first and foremost in this."

After undergoing Tommy John surgery that led to a 17-month recovery, the last thing Lackey wanted was another injury, but he's glad this one appears to be nothing more than a bump in the road.

"I'm not going to throw for a couple days," Lackey said. "I'll just get treatment, that sort of stuff and hopefully get that tight feeling out of there before I start throwing. I mean, I knew it was a little tight. I thought it might loosen up when I threw, but it didn't really loosen up."

Right-hander Alex Wilson, who has never pitched in the Majors, was summoned from Triple-A Pawtucket to take Lackey's spot on the roster. He will pitch out of the bullpen.

Wilson made two appearances for Pawtucket this season, posting a 10.12 ERA over 2 2/3 innings.

Ortiz to play in Pawtucket on Thursday

BOSTON -- Red Sox slugger David Ortiz will be back in New England on Thursday, when he starts a Minor League rehab assignment for Triple-A Pawtucket.

The designated hitter has made significant progress in recent days with his right Achilles, and played in some extended Spring Training games.

The PawSox have an eight-game homestand that begins Thursday, so Ortiz could play all of those games if he needs the at-bats. He could be activated by the Red Sox at some point next week, perhaps for the start of next homestand, which is April 19 against the Royals. It would be more surprising if Ortiz is activated during Boston's three-game series at Cleveland from April 16-18, though the club hasn't ruled anything out.

"His return date to us is still uncertain at this point, and that's going to depend on David and how comfortable he feels in the box with his timing, but we would assume somewhere in the 20 to 30 at-bat range would be expected that he'll need," said manager John Farrell. "More than anything, the last four or five days, he's seemingly has turned the corner with more aggressive running the bases and the way he feels at the plate. He's in a pretty good place right now all things considered."

Highly touted prospect Jackie Bradley Jr. has been holding down Ortiz's spot start in the lineup, playing the outfield while Daniel Nava and Jonny Gomes have shared DH duties.

Bradley had a tough weekend in Toronto, going 1-for-11 and got his first day off in Monday's home opener. He was back in the lineup for Wednesday's game against the Orioles, batting ninth and playing left field.

"John felt like sometimes with a young player, you get to the big leagues, that first week, there's a lot going on, and you can take a day to watch and get back in it," said general manager Ben Cherington. "He still took some walks in Toronto and played defense and was helping the team. We know what he's capable of doing offensively. We expect to see a lot more of that."

Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.