Cole Hamels, one of the Phillies' top pitching prospects, will have surgery on his pitching hand on Thursday after an altercation in Clearwater, Fla., last weekend left him with a fracture of the fifth metacarpal.

Dr. Randall Culp, a hand specialist who examined Hamels at Thomas Jefferson University Hospital in Philadelphia on Monday, will align the fracture with an intermedullary pin during the procedure.

Hamels, 21, is not expected to return to game action until May. Three weeks after the surgery, the pin will be removed. The left-hander will then face three weeks of recovery before he can begin light throwing.

"We are certainly disappointed that this has occurred," general manager Ed Wade said. "Cole is a top prospect who has a chance to move quickly through our system, but he put himself in a position that slows his development, and that is unfortunate."

Hamels, who was invited to Spring Training, is widely considered the Phillies' top prospect. He compliments a low to mid-90s fastball with a devastating changeup and an improving curveball.

However, Hamels made only four starts for Class A Clearwater last season due to elbow soreness.

After watching Hamels pitch in an Instructional League game in October, team personnel said he was on track for the 2005 season. Due to the setback, he will report to the club's minor league camp when it opens in early March.

The Phillies selected Hamels in the first round of the 2002 First-Year Player Draft, and he lived up to expectations with a remarkable 2003 season. He started the year in Class A Lakewood, where he struck out 115 in 74 2/3 innings while posting a 0.84 ERA.

He then was promoted to Clearwater, where he didn't allow more than two earned runs in each of his five starts. Hamels also pitched in the 2003 Hall of Fame game, in which he gave up two earned runs on three hits while striking out nine in five innings against the Devil Rays.

For his efforts, Hamels received the Paul Owens Award as the organization's best minor league pitcher in '03.

Hamels is 7-3 with a 1.31 ERA in 22 career starts in the Phillies organization, amassing 171 strikeouts in 117 innings.