LAKELAND, Fla. -- Tigers outfielder and first baseman Marcus Thames hopes to return to action this weekend after an MRI exam Wednesday revealed no damage in his right knee.

Thames, who hasn't played since last Sunday's game against the Indians in Winter Haven, said Friday morning that he first noticed "something felt different" in his knee when he was taking ground balls before Wednesday's game against the Braves at Joker Marchant Stadium. He wasn't on the trip for Monday's game vs. the Yankees, and he was off Tuesday for a previously scheduled personal matter.

"Just wanted to get it checked out," Thames said. "It was bothering me, so I wanted to make sure nothing was really wrong."

An examination in Lakeland showed inflammation, but nothing structurally to worry about, so he's going to work through it. While the Tigers sent a travel squad to Port St. Lucie to face the Mets, Thames was among the larger group that stayed back in Lakeland for work. Thames hit in the batting cage and worked out in the weight room trying to strengthen the knee.

A return by Sunday would be optimal for the Tigers, who have split-squad games against the Phillies at Clearwater and at home against the Mets. Sean Casey and Chris Shelton have been starting at first base this week, with Mike Hessman playing some of the later innings.

"I just want to be out there giving myself a chance to play," Thames said. "I hate standing back when I need to be out there, especially when I'm trying to learn first base. I can use the games."

Dingman back on mound: Craig Dingman threw an eight-minute bullpen session Friday, three weeks after the last time he threw off a mound, and felt surprisingly well.

"I couldn't ask for a better [session] after that much time. I felt probably 50 percent better than I would've thought," said Dingman, whose comeback was put on hold last month when he was diagnosed with a blood clot in his right shoulder, the same shoulder where he underwent arterial bypass surgery last spring.

Dingman said he threw mainly fastballs and changeups and felt life in his velocity. He'll continue throwing bullpen sessions every other day for the next week or two. There's no set timetable on when he'll pitch to live hitters or when he could pitch in a game.

Most likely, Dingman will stay back in Lakeland when camp breaks to continue working his way back. If all goes well from there, he could end up returning to the bullpen at Triple-A Toledo, where he struck out 67 batters over 48 innings in 2005.

"I just hope I can build on that [session], stay healthy and keep moving forward," Dingman said. "Enough of the setbacks and coming off injuries. I'm done with setbacks. I want to get this injury behind me where I don't have to deal with it and worry about it. That's what I'm looking for."

Colon update: Roman Colon is playing catch from about 60 feet away as he works his arm back into shape following neck surgery last fall. He said he's throwing free and easy without any soreness or pain in his neck, somewhat to his surprise. His process is a matter of rebuilding arm strength after going about seven months without throwing.

The schedule for his return calls for him to start the regular season on the disabled list while he remains in Lakeland to work out. If all goes well, he could pitch in games around the beginning of May.

"I'm careful with this, because if I don't fix this, I'm not going to be able to pitch anymore," Colon said. "What I want to do is to be able to pitch again. I don't care when."

Sheff in the field: The lack of a designated hitter spot Thursday against the Reds meant Gary Sheffield was in the outfield for the first time this spring. While Sheffield said Friday he felt comfortable out in left, he doesn't have any need to play the outfield in any number of games this spring to prepare himself.

Though Leyland told Sheffield before he agreed to last fall's trade that he'd primarily be a DH, Leyland also said he'd end up playing some games in the outfield to give Magglio Ordonez and Craig Monroe some rest. However, Sheffield said he's had enough experience out there that he doesn't need much preparation to be ready for games.

"It was good to get out there just to play the field again," Sheffield said.

Coming up: The Tigers will be back home Saturday in front of what's expected to be a capacity crowd for a 1:05 p.m. ET game against the Red Sox. Justin Verlander will make his second start and third appearance of the spring. Jason Grilli, Jair Jurrjens, Bobby Seay, Jose Mesa and Todd Jones are scheduled to follow in relief. Josh Beckett is slated to start for Boston.