The Astros optioned Cole to Triple-A Sugar Land on Thursday, Brian McTaggart of MLB.com reports.
The 25-year-old outfielder will lose his place on the 26-man roster to make room for LaMonte Wade, who signed a major-league contract with Houston on Thursday. Cole has managed just one hit in 28 at-bats over his last 11 games with the Astros, so moving back to Triple-A could allow him to get back on track.