From Sheldon's Mailbag:
I know I was one of the people decrying the 3 catcher situation because of Hatteberg. I mean, the whole chapter about him in Moneyball mentions clearly his transition from C to 1B. But if his arm is crap...Why do the Reds feel the need to carry three catchers? It is a waste of a roster spot. If you think about it, there are four catchers considering Scott Hatteberg came up as a catcher.
-- Dean F, Loveland, Ohio
Certainly, Hatteberg could step up during an emergency. But he stopped catching long ago because he had a below-average throwing arm. Even he says his throws would get to second base...eventually.
If they carried a third catcher in Chad Moeller, which isn't a guarantee, the Reds would do it to get extra protection -- especially since No. 2 catcher Javier Valentin is their best pinch-hitter from the left side. Without a third catcher, the bench would be exposed if Valentin had to bat and then David Ross got hurt later in the game. If a second lefty pinch-hitter or switch hitter makes the club (ie: Hamilton or Mark Bellhorn), the three-catcher situation might not be happening.
However, late in a game, if he only has to catch an inning or two, I'm not too worried about this. He can still frame pitches and still catch them in the glove. Throwing out runners is the least of our worries if Ross or Valentin get hurt.