"Obviously, the best news would have been that he had been cleared to throw," Mozeliak said. "He's not there yet, and I think, just taking a very proactive stance on this, this is best for him and his career. I'm sure he's frustrated and would like to be a little bit ahead of this, but I think this is just in the best interest of him. Hopefully, by the next time we do another MRI, he'll be clear."
The Cardinals have spent the past few weeks gathering more information about the injury, the root cause and treatment options. Mozeliak said the injury does not appear to be related to Wacha's mechanics but instead is a biomechanical issue that can be aided with strength work.
Monday's update comes a little more than three weeks before the non-waiver Trade Deadline, with the Cardinals still determining what needs they may address, but Mozeliak downplayed the correlation between Wacha's status and the organization's interest in acquiring another starter.
"Well, we expect to get [Joe] Kelly back ... and feel pretty confident that [the five in our rotation] can be successful," Mozeliak said. "There are probably very few pitchers we could go out and acquire without having to give up one of those to begin with. I think that would just make it problematic, so for us, we feel pretty good where we're at from a pitching standpoint."
Speaking more generally about the Trade Deadline, Mozeliak said, "I think you could say we could worry about a lot of things. The right strategy is, if we think there's an opportunity to improve, we'll try. We're not going to make a bad decision just in a panic situation."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. Alex Halsted is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.