Walker, five days removed from his 27th birthday, entered the league with the New Orleans Saints as an undrafted free agent in 2012 and has spent the past two seasons with the Detroit Lions, starting a combined 12 games. Listed at 6-foot-3, 310 pounds, Walker started the first four games of the 2015 season for the Lions, then spent the rest of the year on injured reserve with a broken fibula and a dislocated ankle. He started eight games early in 2016 but was then benched.
Walker finished the season with zero sacks and has totaled 3.5 sacks through 42 career games.
Walker joins a Rams defensive line that features Aaron Donald and Michael Brockers as starters. Robert Quinn and the recently signed Connor Barwin will serve as outside linebackers in a 3-4 set, but will be the defensive ends in nickel formations. The Rams have Dominique Easley, Ethan Westbrooks, Matt Longacre, Morgan Fox and Walker as backup defensive linemen, though one of them could see a lot of snaps when the Rams are in a 3-4.