Wacha is a candidate to start Sunday against the Cubs, Jenifer Langosch of MLB.com reports.
The Cardinals have an opening in their rotation following the demotion of Genesis Cabrera, and Wacha is a candidate for the job. After struggling in his first relief appearance following his move to the bullpen, the right-hander fired 2.1 scoreless innings in a loss to the Reds on Tuesday, allowing just two hits while striking out three.