DT Marcell Dareus and CB Stephon Gilmore did not travel with the team and have been downgraded from Doubtful to Out for the Bills game against New England on Sunday.
Neither player practiced this week after suffering injuries against the Oakland Raiders on Sunday.
Dareus left the game against Oakland with a knee injury and has been one of the most dominant defensive linemen in the league this year, picking up 48 tackles, 10 sacks and one forced fumble. He was named to the Pro Bowl on Tuesday.
Gilmore, Buffalo's top cornerback, suffered a concussion against Oakland. He has 46 tackles and three interceptions.