No corresponding move was made at the time of his demotion, but it's likely outfielder Yoenis Cespedes will take Ross' roster spot when activated from the disabled list Friday in Kansas City. A position player would then be sent out upon right-hander Brandon McCarthy's reinstatement from the DL on Saturday.
Ross lasted five innings in Wednesday's 4-0 defeat in Minnesota, the team's eighth loss in a row, allowing all four runs on six hits and three walks. He was 1-6 with a 7.34 ERA over his past seven starts after going 1-0 with a 2.13 ERA in his first two with the A's, following his April 17 callup.
When speaking to reporters after Wednesday's outing, manager Bob Melvin didn't sound so certain Ross would make his next start with the A's. The 25-year-old was struggling particularly against left-handers, who hit .417 off him.