McCullers (shoulder) struck out four and allowed two hits and no walks over three scoreless innings in a rehab start Thursday with Triple-A Sugar Land.
Pitching in a game for the first time since May 13 after being sent to the injured list due to a right rotator cuff impingement, McCullers delivered an encouraging performance. He mixed in five different offerings in the 42-pitch appearance, averaging 90.9 mph with his sinker while displaying strong control. McCullers had issued 22 free passes in 39.1 innings with the Astros prior to landing on the shelf, so keeping his walks in check in his subsequent rehab outings will be imperative if he hopes to reclaim a spot in a crowded Houston rotation once he returns from the 15-day IL. In addition to their current five starters, the Astros are expected to bring Cristian Javier (shoulder) back from the 60-day IL later this week, and Ronel Blanco (elbow) is also in the midst of a rehab assignment and could be an option for the rotation around the same time McCullers is ready for activation.