"I don't think a place has ever meant more to anyone than what Buffalo means to me," Williams told reporters Friday. "It's always going to hurt walking away from this game, but I know it's the right time."
Williams entered the league in 2006 as a fifth-round pick with the Bills, and became a mainstay on the defensive line. With one game to go, he has appeared in 182 games with 177 starts, totaling 607 career tackles (384 solo) -- 102 for a loss -- 48.5 sacks and 141 quarterback hits.
Age also hasn't slowed down his production, as the 35-year-old Williams enters Week 17 ranked second among defensive linemen with 620 total defensive snaps on the season, four behind defensive end Jerry Hughes (624).