Running Back (4)
James Cook, Damien Harris, Nyheim Hines, Reggie Gilliam
There are a number of positions that the Buffalo Bills could consider reducing the depth to create that extra spot for the third quarterback. However, the one position that I believe the front office finds that extra spot will be at running back.
In the past, the Buffalo Bills have typically had five running backs/fullbacks on their 53-man roster with Reggie Gilliam earning that extra spot. However, Gilliam is a key part of special teams and in addition to fullback, can play some at tight end.
When looking specifically at the running back position, the fourth running back has been Taiwan Jones. However, he wasn't much of a factor on offense and was a primarily special teams player.
The Bills don't really have a running back on the roster that fills that role and with the offense leaning heavily into the passing game, they can afford to have less depth at running back.