Another position where it will only be a concern if the starter is forced to miss extended time is at center. However, unlike quarterback the chances this is a reality are much higher as Mitch Morse has missed at least one game in two of the past three seasons.
The Buffalo Bills presently don't have a clear option to back up Mitch Morse but seem to have some options if the need were to arise. One player would be Ryan Bates, who was the starting guard last year for the Bills. However, he likely won't keep that spot and be utilized more in a backup position between guard and center.
Another player is Greg Mancz, who spent the majority of the season on the practice squad last year and appeared in one game. He was released midway through the season but the Bills did re-sign him this offseason. Mancz is probably a long shot to make the roster but if he does it will be to back up Mitch Morse at center.