The Guardians optioned Allen to Triple-A Columbus on Sunday.
The left-hander served as the 27th man for Saturday's doubleheader against the Pirates and started the nightcap, taking a no-decision after giving up three runs (two earned) on six hits with three strikeouts and three walks over 3.1 innings. Allen will rejoin Columbus' rotation but could get another look in the majors when Cleveland needs some length.