Houser exited his start Thursday against the Pirates with an apparent injury, Adam McCalvy of MLB.com reports.
Houser came out after throwing 2.1 innings, though the cause of his discomfort was not clear. He surrendered three earned runs on five hits -- including a pair of homers -- and a walk. Milwaukee's rotation is getting healthier, but if Houser is forced to miss any time it would likely force Chi Chi Gonzalez to stick in the starting five.