ARLINGTON, Texas (AP) _ Texas Rangers left-hander Justin Thompson had arthroscopic surgery Friday to repair a torn rotator cuff in his throwing shoulder.

During the two-hour operation, the tear was repaired and an area on his shoulder that had been repaired last August was cleaned.

Dr. John Conway, the Fort Worth physician who performed the surgery, said the procedure went as expected.

Thompson had been on the disabled list all season while recovering from shoulder surgery in August. He came to the Rangers in an off-season trade with the Detroit Tigers for Juan Gonzalez.

Thompson, who will be sidelined the entire season, is expected to wear a sling for about three weeks and won't start throwing for another four or five months.

The Rangers also announced infielder Frank Catalanotto, who has been on the disabled list since pulling his left groin muscle April 21, was sent to Oklahoma of the Pacific Coast League on a rehabilitation assignment. He was scheduled to play for the RedHawks against Iowa on Friday night.