To play RT, then the team that gave him a contract according to that position moved him to LT. He moved, played at a Pro Bowl level and now he wants more money. It's the natural thing to do.
Now, lets pretend the team moves him to QB, he says yes, kicks some ass throwing to TO and Evans and goes to the Pro Bowl, my guess is that he will be asking for more money.
If you would have been promoted to a better position in your workplace but with the money from the previous position you too would be asking for better money.