Allen was reassigned to the Guardians' minor-league camp Sunday, Mandy Bell of MLB.com reports.
Allen was with the big-league club to open spring training but unsurprisingly won't make the Opening Day roster. He earned a mid-season promotion to Triple-A Columbus last year but struggled at the highest level of the minors with a 6.49 ERA, 1.57 WHIP and 73:29 K:BB over 59.1 innings.