McCullers (shoulder) will begin a rehab assignment with Triple-A Sugar Land on Thursday, Brian McTaggart of MLB.com reports.
McCullers threw a 25-pitch live batting practice session Friday and has now been cleared for game action in the minors. The veteran right-hander has been on the shelf for a month due to shoulder inflammation and could back with the Astros after making a couple rehab starts, depending on how well he's able to build up his workload.