"The Indians probably have lost two-thirds of their starting outfield until early September, if not longer.

Grady Sizemore underwent surgery Thursday — not on his right knee, which ostensibly has been the problem — but for a sports hernia.

Dr. William Meyers performed a 20-minute procedure in Philadelphia to repair a hernia that developed after Sizemore slid into second base May 11 and also banged up his right knee.

Head trainer Lonnie Soloff said the club has known about the hernia all along.

"During the event in May, Grady complained about right-hip (sports hernia) and right-knee pain," he said. "We knew it [sports hernia] would have to be addressed in the offseason. But he thought he could play with it until then."

The plan changed because Sizemore is on the disabled list anyway with the right-knee contusion.

Expected recovery time from the operation is four to six weeks. "We are cautiously optimistic that Grady will play again this season," Soloff said.

Six weeks would put Sizemore's return about Sept. 1, but there is no guarantee that he will be fully healthy by then and have regained his normal timing and rhythm at the plate.

Right fielder Shin-Soo Choo, who is on the disabled list with a fractured thumb, is expected to return to the lineup shortly before or after Sept. 1, but the same cautionary factors apply to him as with Sizemore.

Sizemore tends to put himself in jeopardy because he plays with reckless abandon.

"Grady plays very aggressively, and sometimes injuries result," Soloff said. "But that's what makes Grady Grady. He plays all-out. It's difficult to ask someone to change the way he plays, because that could lead to other compensatory injuries.""