The Guardians optioned Pilkington to Triple-A Columbus on Wednesday.
Pilkington was sent back to the minors one day after suffering his first career MLB loss. He picked up his sixth big-league start in the second game of a doubleheader with the Twins, covering 4.1 innings and striking out four while allowing four runs on eight hits and three walks. The Guardians will have a need for a temporary sixth rotation member once again Monday in Detroit, so Pilkington will be a prime candidate to receive a call-up from Triple-A to make a spot start.