The 28-year-old Dunbar enjoyed a career year in 2012, setting career-best marks in combined tackles with 115 and sacks with 4.5. He also had the first two interceptions of his career and forced two fumbles.
Dunbar spent four seasons with the New Orleans Saints before signing with the Rams in advance of the 2012 season. He will be suspended without pay until the team's Week 5 game against the Jacksonville Jaguars. Dunbar can continue to participate in training camp and preseason games while serving his suspension.
With Dunbar's suspension, more than a dozen players have been suspended heading into the 2013 season. In Dunbar's absence Will Witherspoon is likely to get snaps at the strongside linebacker with rookie Alec Ogletree playing weakside linebacker.