Wacha (oblique) will throw a bullpen session at Coors Field prior to Sunday's game and then head out for a Tuesday rehab start at Double-A Springfield, Joe Trezza of MLB.com reports.
The right-hander looked much steadier in his Thursday appearance for High-A Charlotte than he had in his first rehab start five days prior. Wacha is slated to work up to 75 pitches at Springfield on Tuesday, a significant bump up from the 49 he threw Thursday. Interim manager Mike Shildt indicated Friday that Wacha could be ready for a return if he tolerates the workload well, with the Cardinals skipper describing him as being "in the conversation" to resume pitching in early September.