I would assume that pitching in the game, sitting on the bench, then warming up and throwing again is hard than we make it out to be. It's probably not the same as getting 3 outs in clean situation. I'm sure Cora knows how awful his relievers have been and isn't trying to put them in bad situations. He's just stuck with the guys he has.
Bailey Horn?
Cam Booser?
Chase Shugart?
These aren't guys you can count on. Kelly, Winckowski and Garcia are a different issue.