Houser underwent Tommy John surgery Thursday and will miss 12-to-18 months, Todd Rosiak of the Milwaukee Journal Sentinel reports.
Houser had been stationed at Double-A Biloxi this season, where he held a 5.25 ERA and 1.393 WHIP across 13 starts (70.1 innings). The 23-year-old, a second-round pick of the Astros in 2011, is expected to miss all of the 2017 season, with the very slight possibility that he could return to pitch a handful of innings near the end of the year, if he recovers more quickly than the 12-to-18-month timetable would suggest.