No one seems to understand the postseason eligibility list this year, myself included, so I'm going to go ahead and guess this is very precautionary if we had an injury to Abreu or something.
Id rather have EE at DH than Mazara.
But aside from that, this isn't on RR. It's on the FO for not giving him a 3rd catcher. EE is a useless roster spot if he isn't the dh since he can't do anything else. Its in the FO to get rid of him.