The Astros placed Sousa on the 15-day injured list with left elbow inflammation Friday, Matt Kawahara of the Houston Chronicle reports.
It's not clear when Sousa's elbow began barking, but his last appearance came Tuesday in Detroit. He'll be eligible to return Sept. 4, but it's possible he'll need more time, given the nature of the injury. It's a blow to the Astros' bullpen, as Sousa holds a 2.84 ERA and 59:15 K:BB over 50.2 innings this season.