In the game against the New York Giants, running back Damien Harris suffered a scary neck injury and had to leave the game in an ambulance. The news since then has been positive and is out of the hospital and resting at home.
It remains to be seen when he might be able to return but it won't be this weekend against his former team the Patriots. Without Harris, the Bills could call up Ty Johnson from the practice squad but the team is more likely to shorten the rotation down to just James Cook and Latavius Murray.
From Week 2 through Week 6, Harris was averaging about five carries per game which now likely goes to Latavius Murray, who was averaging about four carries per game during the same stretch. In the game against the Giants, Murray finished with 12 total and it wouldn't be surprising to see him have close to the same while playing about half of the offensive snaps against the Patriots.