The Twins placed Ryan on the 15-day injured list Friday with a left glute strain.
Imaging revealed the injury Thursday, and it's unclear at this point if Ryan will need to miss more time than the minimum 15 days. With Ryan off to the injured list, Zebby Matthews has been summoned back from Triple-A St. Paul and will start Friday's game against the Brewers. Ryan owns a 3.65 ERA, 1.14 WHIP and 138:27 K:BB across 125.2 innings spanning 23 starts this season.