Ponce de Leon (shoulder) will start a rehab assignment and throw an inning for Triple-A Memphis on Thursday, Jeff Jones of the Belleville News-Democrat reports.
A right shoulder injury has sidelined Ponce de Leon since June 23, at which point he had pitched to a 7.03 ERA in 24.1 innings. It's unclear how many appearances he'll make before being activated, but the Cardinals' desperate need for starting pitching suggests they'll stretch the 29-year-old out a bit to make him a viable option for the rotation.