The Bills placed fullback Patrick DiMarco on season-ending injured reserve Friday, the team announced.
DiMarco, 31, injured his neck during training camp.
He has appeared in 48 games with 18 starts the past three seasons for the Bills with 21 touches for 145 yards.
DiMarco saw action on 599 offensive plays and 557 on special teams the past three seasons combined.
They activated tight end Tommy Sweeney from the active/physically unable to perform list. Sweeney began training camp on the list with an injured foot.
Sweeney, a seventh-round draft pick in 2019, spent all of last season on the active roster. He played six games, catching eight passes for 114 yards.