A review by Dr. James Andrews of Joba Chamberlain's most-recent MRI results confirmed what the Yankees already believed: Their key setup man needs Tommy John surgery.

Chamberlain, who was diagnosed with a torn elbow ligament by team doctors Wednesday, will undergo season-ending surgery performed by Dr. Andrews next Thursday, Joe Girardi announced before Friday's game against Cleveland.

"I was pretty settled that he was going to have the surgery," Girardi said.