PITTSBURGH -- Left-hander Donnie Veal will undergo Tommy John surgery on Friday after being diagnosed with a torn ulnar collateral ligament in his left elbow. The diagnosis was given by Dr. James Andrews after Veal visited the orthopedist on Thursday.

The procedure will cost Veal the rest of the 2010 season, and the recovery time for this type of surgery is typically 12-18 months. Veal, who pitched out of the Pirates' bullpen as a Rule 5 Draft pick in '09, was one of the organization's best starting pitching prospects in Triple-A.

Veal was 3-2 with a 4.35 ERA in nine starts for Indianapolis before the injury. He had struck out 41 and walked 23 in 49 2/3 innings.

The left-hander is now the second member of Indianapolis' rotation to undergo season-ending surgery already this year. Andrews performed surgery on Kevin Hart at the beginning of May to repair a torn labrum in Hart's right shoulder.

A statement from a club spokesman on Thursday said that the Pirates will provide further information on the injury and procedure on Friday.