Williams missed the Bills last two games with a back injury.
A first-round pick of the Chicago Bears in 2008, Williams spent parts of five seasons with the team before moving to St. Louis in 2012. Williams joined the Bills as a free agent in March, signing a four-year deal worth $13.5 million.
Buffalo promoted safety Kenny Ladler to the 53-man roster. He joined the Bills as an undrafted free agent out of Vanderbilt but was released before the start of the regular season.