Walter will start Sunday against the Guardians, Brian McTaggart of MLB.com reports.

EDGE Analysis

Walter joined the Astros as part of the taxi squad, hinting at the potential for him to start Sunday. That is now confirmed, though a formal roster move will come later Saturday or Sunday. Walter made a spot start with the Astros on May 20 and delivered five shutout innings with a 5:1 K:BB against Tampa Bay.