The Guardians optioned Dion to Triple-A Columbus on Sunday.
The left-hander spent most of June and July in the big leagues but has been shuttled between Triple-A and the majors a few times since the All-Star break. In his first taste of MLB this season, Dion has a 4.58 ERA, 1.37 WHIP and 25:3 K:BB across 19.2 innings. Trade acquisition Craig Yoho will fill the vacated roster spot for Cleveland.