Carpenter was examined Tuesday in St. Louis and will rejoin his teammates in Florida, where he will receive treatment from the team's medical staff.
The 2005 NL Cy Young Award winner, Carpenter was injured in the sixth inning of Sunday's 6-2 loss at the Chicago Cubs. He was making his third start since Opening Day last year. The right-hander underwent elbow ligament replacement surgery in July 2007.
St. Louis began exploring its options even before Carpenter's test results were in.
Cardinals pitching coach Dave Duncan said Carpenter's replacement would come out of the bullpen, according to multiple media reports. Duncan mentioned Brad Thompson and Jaime Garcia as options. Both pitchers have starting experience and neither pitched in Tuesday's 4-3 loss to the Florida Marlins.
Thompson has made 19 appearances this season, three of which were starts, and is 4-2 with a 4.34 ERA. Garcia, meanwhile, has made six appearance with one start. He is 1-1 with a 3.27 ERA.
Information from The Associated Press contributed to this report.