by Jon Paul Morosi

"He now feels he should be able to come back (this season), maybe even by early July," Greenberg said Sunday. "It will depend on how he continues to progress. Ideally, the Tigers would like him to be able to come back and play left field, which would take him a bit longer to get to that point."

Greenberg said Guillen, 33, is hoping to avoid offseason surgery on his right shoulder, but it has not been ruled out. "We'd have to see how he does when he comes back and at what level he can perform," Greenberg said.

Guillen has consulted with three surgeons and been diagnosed with stretched ligaments, some rotator cuff fraying and a bone bruise. He hasn't played since May 4 and was batting only .200 when he was placed on the disabled list.

Greenberg previously said there could be a drop-dead date on the decision to have surgery sometime in July, in order to afford Guillen the best chance at making a full recovery before the 2010 season. After this season, two years and $26 million will remain on the $48 million deal he signed in 2007.

Either Marcus Thames, a right-handed batter, or Don Kelly, a left-handed batter, has started the Tigers' past nine games in left. Thames (five home runs, 63 at-bats) is the bigger power threat, while Kelly is batting .417 in nine games this season.

The Tigers' outfield will be watched closely in the weeks to come. They have been looking for a power bat on the trade market, and the recently benched Magglio Ordonez is likely to return to the lineup in this week's home series against the Cubs.