KANSAS CITY, Mo. (AP) -- Kansas City Royals' left-hander Mark Redman underwent arthroscopic surgery on his left knee Monday to fix a lateral cartilage tear.

A team spokesman said the surgery was performed in Kansas City by Dr. Steve Joyce, the team physician. There was no immediate word on when Redman would return.

Acquired in a December trade with Pittsburgh, Redman was being counted on to be in the starting rotation.

The team said Redman would be re-evaluated next week at the Royals' spring training camp in Surprise, Ariz.

Redman had swelling in the knee after a two-inning start Thursday against the Texas Rangers. He was scheduled to start on Monday against the San Diego Padres, but the swelling did not subside.

Redman was 5-15 with a 4.90 earned run average in 30 starts in 2005 with Pittsburgh. He has a 53-66 career record with a 4.47 ERA, and the Royals are his sixth club since 2000.

Redman's injury is the second spring training blow to the already thin Royals' rotation. Right-hander Zack Greinke left camp eight days ago for undisclosed personal reasons. The club granted him permission to return to his home in Orlando, Fla., but have no timetable on when he may return.

Scott Elarton, a free agent sign from Cleveland, and Runelvys Hernandez, who reported to camp several pounds over his listed weight of 250, are the only certainties for the rotation if Redman and Greinke are not ready by early April.

Other rotation candidates are right-handers Joe Mays, Denny Bautista and Mike Wood, and left-handers Jeremy Affeldt and J.P. Howell

"We have some depth," manager Buddy Bell said. "It just makes it that much more competitive. There are a lot of openings."