Valdez is expected to be called up to start Thursday's game against the Rangers, Jake Kaplan of The Athletic reports.
With Jose Urquidy getting sent to Triple-A Round Rock on Wednesday, the Astros have a gap in the rotation. Valdez is in line to start Thursday and has big-league experience this season, so he's the logical choice. He hasn't been particularly effective in 45.1 major-league innings this season, recording a 4.57 ERA. His 20.8 percent strikeout rate and 9.6 percent walk rate are each slightly worse than average, though his 59.4 percent groundball rate is strong.