Poncedeleon was optioned to Triple-A Memphis on Wednesday.
Poncedeleon lasted just four innings Tuesday in his first start after earning a rotation spot that appeared to be a permanent one. The move may have little to do with the pitcher's performance, however, as the Cardinals have off days Thursday and Monday and won't need a fifth starter until Sept. 1, the day Poncedeleon would be eligible to return. It remains to be seen whether or not he'll get the ball that day, but the demotion doesn't necessarily mean the Cardinals have lost faith.