McCoy is expected to be out for at least 3–4 weeks after telling reporters that he suffered a Grade 2 hamstring pull Friday. McCoy aggravated the injury during practice before the team’s Week 3 game.
Williams has been sidelined since suffering a concussion during a 24–10 loss to the New York Giants on Oct. 4.
Despite lacking depth at running back, the Bills have been solid in the running game this year, ranking sixth in the NFL with 513 total yards. Much of that has come from Williams, who has 226 rushing yards and three touchdowns on 42 carries.
Boobie Dixon will handle the bulk of the carries Sunday. He has found the end zone once on eight carries.