The Astros placed Okert on the 15-day injured list Friday with a right hamstring strain, Chandler Rome of The Athletic reports.
It's unclear when Okert was hurt, but he hasn't pitched since Monday. He's been dynamite out of the Houston bullpen this season, logging a 2.13 ERA, 0.87 WHIP and 68:14 K:BB over 67.2 innings. Bryan King will absorb Okert's spot on the roster and in the bullpen.