Ive heard rumors that hes already said his plan is wait until the last possible moment and sign so he gets credit for the year. if this is the case, consider the patriots and their position.
As i see it, the patriots have 3 options, and none of them are particularly attractive.
1. Pay Mankins what he wants;
This is great if you dont mind spending 8-9 mill per year on a guard, the pats have reportedly already offered him around 7m y/r , keep in mind also that the offensive line is one of the strengths of this team atm with some more depth in nick Kaczur coming back you'd have an overabundance of depth at the position and be pretty close to overpaying.
2. Trade Mankins;
Convince Mankins to come in and sign him to a deal for the sole purpose of being able to trade him, he is not signed by the patriots ATM which means they cannot make any trade involving him. at this stage in the season and given the fact that he is going to want a new lucrative contract right away with his new team, the best possible draft pick you could probably get would be a 3rd or a 4th, maybe some dumb team offers you a 2nd but probably not.
3. Wait til he signs his tender late in the season.
At this point the trade deadline has passed and he would be playing simply to get out from under the restricted free arent tender next year and become an unrestricted free agent, i can only assume that he would be a bench warmer til the end unless some kind of injury happens.
#3 is the most unfortunate scenario and also the most likely, people say that all of the power is in the patriots court, but the more the season progresses, the less control the patriots have over Mankins as his value decreases.