Winston backup options?

Ideally Winston comes back and plays lights out and earns a new contract. (I am hoping for Rivers and a high qb draft pick, or better yet trade for Carr). But, if we hold on to Winston, which I believe should be for less than the tag, he has to have a viable backup if he flatters in the first quarter of the season (ie looses games with picks the defense should’ve won), he needs to be yanked.

Who would be reasonable options for the backup spot that we wouldn’t waste a good defensive season and have a chance at the playoffs? Dalton? Mariota?