Would quarterbacks like Peyton Manning or Tom Brady ever leave for another team?

dwurfur007 asked:


If another team offers Peyton Manning or Tom Brady a better contract, what are the odds they would leave their current team? If they were to refuse, why? Are they even allowed to accept or are they too closely on a leash by their coaching staff?

I just think about what the Colts and the Patriots would be without their respectable quarterbacks and it sends chills down my spine.