The Guardians recalled Allen from Triple-A Columbus on Monday.
Allen will start the second game of Monday's doubleheader against the Royals. The lefty could be in line for just a spot start, as Alex Cobb (fingernail) looks to have a good shot and returning from the 15-day injured list the next time the Guardians require a fifth starter. Allen holds a 5.56 ERA, 1.54 WHIP and 78:37 K:BB across 92.1 innings with the big club this season.