Earlier than my time, so I'm not aware of the details, but I do know that a fireballer is going to have less trouble with a blister than say a junkballer. When Lincecum was dealing with blister problems, it was his curveball that was suffering. He was able to continue throwing his four-seam fastball without any problem. Having said that, I'm not ready to attribute Maya's problems to a blister. I think it is a bunch of external factors pressuring him at once. Let him adjust to the league now in September, then let him compete for a spot in ST.
Beckett's was caused by his curve also. It happens most when pitchers switch balls (college to pro, minors to majors, Japan to US) I think Cuba still uses the horse hide ball so Maya's problem might simply be a case of adjusting to the slicker cow hide ball.