The surging Athletics won't have Trevor Cahill on the mound Saturday.
The right-hander had been scratched from his scheduled start at Tampa Bay with a rhomboid (upper back) muscle strain.
Cahill has returned to Oakland for an MRI. Oakland wrapped up a three-game series at Baltimore on Thursday night.
Manager Bob Melvin told reporters Thursday that he's hopeful Cahill (6-3, 3.77 ERA) can pitch on the team's next homestand, which begins Tuesday vs. the Angels.
Oakland has been plagued with season-ending injuries to pitchers. Daniel Gossett, Kendall Graveman, Jharel Cotton and A.