The right-hander, who keyed the Cardinals' run to the World Series in 2013, had an MRI on his shoulder Monday, according to general manager John Mozeliak. The results left the Cardinals training staff confident that Wacha could start throwing again.
"It's shown a lot of healing," Mozeliak told reporters, according to the St. Louis Post-Dispatch. "The inflammation appears to be down in that area. Now, he's ready for that next step."
But Mozeliak said the team remains optimistic that Wacha will pitch again this season.
"At the end of the day, it's whether you do or you don't," Mozeliak said. "But 'optimism' is a fair word right now."
Wacha, 23, is 5-5 with a 2.79 ERA this season.