Wacha will be skipped in his next turn through the rotation as Miles Mikolas will start Sunday against the Pirates, Derrick Goold of the St. Louis Post-Dispatch reports.
Wacha lined up to start Sunday but the Cardinals will instead take advantage of Thursday's scheduled off day and bump up the rest of the rotation one game. The 28-year-old figures to be available out of the bullpen this weekend since the team won't require a fifth starter for at least another week. Wacha has struggled for most of the season with a 5.54 ERA, 1.65 WHIP and 72:42 K:BB in 89.1 innings.