Wacha will have his turn in the rotation skipped to allow him to get extra rest, Jenifer Langosch of MLB.com reports.
Wacha was originally scheduled to start Saturday's bout with the division-rival Cubs, but after going six or more innings in each start thus far, the Cardinals are opting to get him a bit of time off. It's unclear who will fill in for him Saturday, but if he returns to the rotation for his next scheduled start, it would likely come May 20 against the Giants.