Or they could just keep him because he's been good and merely had a bad game with the luxury of an eight-run lead that did not get close to being blown. The epitome of a mop-up guy's job, to pitch in meaningless situations and save other arms. It's just that he was being used in tighter situations recently (and deservedly).
They kept him over Vasquez, they kept him over optioning Marte (who probably has better stuff but can't pitch consistently), they kept him over Ortiz. It's not just because he can't be optioned, they like him.