St. Louis Rams linebacker Jo-Lonn Dunbar draws 4-game suspension St. Louis Rams linebacker Jo-Lonn Dunbar tackles the New York Jets Bilai Powell at Edward Jones Dome in St. Louis, Nov. 18, 2012. LOUIS, Aug. 14 (UPI) -- St. Louis Rams linebacker Jo-Lonn Dunbar has been suspended for four games after a positive doping test, the NFL announced Wednesday. Dunbar won't be able to play until the Rams' Oct. 6 game against Jacksonville after being cited for use of a performance-enhancing substance. The linebacker, who racked up 115 tackles, 4 1/2 sacks and two interceptions while starting all 16 games for the Rams last season, denied he knowingly used PEDs. "First and foremost, I just want to say I did not take a performance-enhancing drug," Dunbar said in statement issued to ESPN. I mistakenly took something that prompted a failed drug test. I want to say that I sincerely apologize to my teammates, the organization, (head) Coach (Jeff) Fisher, (Rams General Manager Les) Snead, my family and friends. I am deeply saddened by this but I plan to serve my four-game suspension and get back to playing football as soon as possible. The 28-year-old former undrafted free agent played four years with the New Orleans Saints before signing with St. Louis prior to last season. He will be able to play in St. Louis' three remaining pre-season contests and participate in training camp practices.