Martinez was placed on the 10-day disabled list due to a right lat strain Thursday.
This is the first news of any injury, so it's unclear when the injury occurred or how severe it is. It may go to explain his poor performance Tuesday, though, in which he allowed four runs in five innings against the Twins. Martinez will have to miss his scheduled start Sunday, but there's still hope he could make his following scheduled start May 19. Mike Mayers will come up from the minors to replace him on the active roster, but it's unclear who will start in his place Sunday.