Whitley (1-0) tossed five scoreless innings, allowing one hit and two walks while striking out six for Low-A Quad Cities on Tuesday.
Whitley, the Astros' first-round pick in 2016, was making his debut for a full-season affiliate. The 19-year-old Texan has a powerful arm and an advanced feel for pitching, so we won't be surprised if he skates through the Midwest League.