Weaver, who was placed on the 7-day disabled list Sunday, has been diagnosed with lower-back stiffness and faces an unclear timetable for a return, Jenifer Langosch of MLB.com reports.

EDGE Analysis

After Weaver was pulled early from his start with Triple-A Memphis on Thursday, it was initially speculated that the injury was related to his pitching hand, but the back was instead the source of his discomfort. The Cardinals should have a better idea of how much time Weaver might miss based on how he progresses from the injury in the coming days, but he'll likely be shut down for the time being as he waits for the back pain to subside.