Fantasy baseball catcher dilemma?

If you're going to shop one of the two, shop Avila. Mauer has to prove he can stay on the field, so his value is very low right now and he won't get you anybody back. If I was in this situation I would probably hold onto both and see if Mauer proves himself. If Mauer goes on a hot streak, then trade hiim and keep Avila assuming Avila keeps it up.