Mankins reportedly did not travel to Buffalo with the Patriots on Saturday evening. He did not practice all week due to a hip injury.
Without Mankins, the Patriots are expected to start fifth-year guard Donald Thomas on Sunday. He started the team's Week 2 loss to Arizona, and has 15 career starts.
Also on Saturday, the Patriots re-signed center/guard Matt Tennant, a veteran who was released by the Patriots earlier this month.