The Cardinals and co-ace Chris Carpenter confirmed Tuesday that the former National League Cy Young Award winner will undergo surgery July 19, a procedure that includes removal of a rib, to alleviate a nerve-related condition that has plagued the righthander for at least four years.

"I want to pitch again," Carpenter said. "This is the only thing that's going to give me a chance to do that."

Surgery to alleviate Carpenter's thoracic outlet syndrome is now considered a necessity, whether or not he pitched this season. Given the halting pace of his return from a condition that sidelined him in spring training, Carpenter opted to seek the procedure soon in order to optimize his chances of returning next February.