Matzek has no structural damage in his left shoulder and has been shut down from throwing for a couple weeks before being re-evaluated, Mark Bowman of MLB.com reports.
The left-hander underwent an MRI after landing on the injured list with shoulder inflammation Tuesday, and he's avoided a more serious injury. Matzek figures to be sidelined until at least mid-June, as he'll need some time to build his arm back up after the shutdown.