ATLANTA — Chris Carpenter, the 2005 NL Cy Young winner, will miss the rest of the season and part of next year after he undergoes elbow ligament replacement surgery next week.

Carpenter hasn't pitched since allowing five runs in six innings of a season-opening loss to the New York Mets.

The right-hander, who went on the disabled list April 2, had arthroscopic surgery to remove bone spurs in his elbow on May 9. He developed swelling and stiffness after a rehab start on July 8.

Carpenter consulted with three orthopedists before deciding to have the procedure commonly known as Tommy John surgery.

"Carp coming back was huge for us," manager Tony La Russa said Thursday, before his team played the Atlanta Braves. "If he's not coming back, you need to factor that in. But we've been a little over .500 with this group out there. The games go on."

By The Associated Press