The Guardians optioned Gaddis to Triple-A Columbus on Saturday, Mandy Bell of MLB.com reports.
Gaddis has been inconsistent in the majors this season -- he has three scoreless multi-inning appearances alongside four starts in which he allowed three runs or more. If he's able to right the ship in Triple-A, there's a chance he rejoins the big club later this season. For now, Michael Kelly will take Gaddis' spot after being selected from Columbus on Saturday.