By Larry Fine

NEW YORK (Reuters) - New York Yankees reliever Joba Chamberlain was found to have a ligament tear in his pitching elbow and will likely miss the rest of the season, manager Joe Girardi told reporters Thursday.

The injury was revealed by a test done on the burly right-hander, who had been placed on the 15-day disabled list Wednesday with what was thought to be a strained muscle.

"The interesting thing about this is if you do every strength exercise on Joba, he passes it with flying colors," Girardi said.

"And he has no idea when it happened. He's pitched. He played long-toss yesterday and his power was there. He said it was a normal long-toss for him, so it really has us all kind of scratching our head."

Girardi said Chamberlain would be getting another medical opinion, but was likely headed for surgery that would end his season.

Chamberlain was 2-0 with a 2.83 earned run average in 27 appearances.

Losing Chamberlain would further hurt a depleted bullpen that was considered one of the team's strengths going into the season.

Also on the disabled list were set-up man Rafael Soriano and lefty specialists Pedro Feliciano and Damaso Marte.

(Editing by Mark Lamport-Stokes)