It also strikes me as smart coaching; you see your QB getting killed either because the line is bad or he cant quite see the protections (or a combo of both), why risk getting him hurt for the rest of the year when what you need anyway is a guy to take some risks in a comeback? Broncos did this with Peyton/Brock in their SB year...Peyton was hurt and bad and they turned to Brock when needed. And when they needed something different, Peyton went back in. Fitz said all the right things after the game too...which is doubly impressive since he was clearly frustrated at being replaced at the bye but has transitioned into this role.