Carpenter (oblique) has been sent to Double-A Springfield to begin a rehab assignment.
What would have been Carpenter's first rehab game was rained out Thursday, but he's been cleared for game action after missing the last month with a right oblique strain. It's not clear how many rehab at-bats the 38-year-old will need before being activated. Once he does return, he'll give the Cardinals another option at designated hitter.