The Guardians optioned Heuer to Triple-A Columbus on Friday.
With Peyton Pallette back from paternity leave, Heuer will return to Columbus, where he owns a 2.57 ERA, 1.21 WHIP and 12:7 K:BB across 14 innings. He's pitched in two games for Cleveland this season, allowing one run on three hits and one walk with three strikeouts covering 2.2 innings.