A AA catcher cannot seriously be compared to a guy in the majors... You're joking?
While a bat's not the end all, be all for a catcher, he was never really known to be a strong defensive catcher, so there's that. He's on the 40-man still. He'll get the call in Sept. if he's healthy.
Usually you have a 4th catcher on the 40man just in case one gets hurt. I dont think he will get the call. Probably only see Severino.