It really depends. Not many, if any, teams in the NFL really have a backup that they are saving just for injuries. Dalton is pretty firmly in as the starter despite AJ's 5 games last year. So I really think the Bengals would probably play around with the Vikings situation and see what they can get out of it because sooner or later they are going to have to make a decision on AJ's future and what they can make out of it. While his name is hot right now is probably the best time. But it's the Bengals, so who knows.
If I was to guess they are going to pass on the Vikings trade and really amp up trade possibilities either that the end of this year or the start of next year.
True. I think after this season they don't owe Dalton that much more guaranteed money though. IF Dalton were to really struggle this year and/or Marvin Lewis gets fired I could see the Bengals management making a decision to go with McCarron over Dalton. It would save them a ton of cap space and they would be getting the same or better production..