The Bills have fired assistant coach Juan Castillo, Jason La Canfora of CBS Sports reports.
Castillo, 59, served as the Bills offensive line coach and run-game coordinator the past two seasons.
Castillo has coached in the NFL since 1995 when he joined the Eagles. He stayed there, in various positions, including defensive coordinator, until the 2012 season ended.
Castillo spent four seasons in Baltimore before the Bills hired him.
The Bills ranked 30th in total offense, including ninth in rushing this season. They allowed 41 sacks.