Brown had his contract selected by the Astros on Thursday.
The 24-year-old has a 2.55 ERA, 1.08 WHIP and 134:45 K:BB over 106 innings with Triple-A Sugar Land this year and will now receive his first taste of the big leagues. Brown has primarily worked as a starter in the minors but is likely to fill a multi-inning role out of the bullpen for Houston down the stretch.