The Patriots are seeking a first-round draft pick or a high second-round selection for the two-time Pro Bowl guard, according to the source. Mankins has refused to sign his contract tender, and no team has met the Patriots' trade threshold to this point.
Mankins also is seeking a deal worth about $8 million per season -- which would put him in line with the top interior linemen in the game. If he isn't traded, Mankins will have to report by Nov. 16 to ensure he gets an accrued season and will not be a restricted free agent again.
According to league sources, Mankins plans to sign his tender by then if he isn't dealt.