Should Bengals keep 2 or 3 QB's

[*ochocincos*]

McCarron has not looked very good so far this preseason. His value has (somewhat) fallen since the offseason. Not really a point to trade him now honestly.
What I'm worried about is what position should/can the team go light on in order to keep a third QB?
As difficult as it may be, a team with an established starting QB shouldn't carry a third QB. That last roster spot is better off going to someone who can play ST at least.