Wacha (oblique) is expected to be out multiple weeks after an MRI revealed a "moderate" strain, Joe Trezza of MLB.com reports.
The Cardinals sent Wacha for an MRI after placing him on the disabled list earlier Thursday. The multi-week timetable puts Wacha's status up to the All-Star break in question, meaning that the Cardinals' thinned-out rotation is taking another significant blow. John Gant was recalled Thursday and could start in Wacha's place Monday.