Dareus was arrested in May 2014 for felony possession of synthetic marijuana and entered the NFL's substance abuse program in July. He entered a pretrial intervention program and will have the charges dropped if he adheres to the terms of the program.
"Last year, I made a mistake involving possession of a banned substance," Dareus said in a statement. "The NFL's discipline for this conduct is part of the drug policy, and I apologize to my family, my teammates, the entire Bills organization and Bills fans that I will miss one game as a result of my mistake. I will work intensely that week and will be extremely happy to contribute to a win in week two for the Bills."
Dareus was a Pro Bowl and First Team All-Pro selection last season after totaling 10 sacks and 35 tackles in 15 games.
Dareus was also arrested near Buffalo last May after crashing his Jaguar into a tree while allegedly racing teammate Jerry Hughes. He was charged with two misdemeanors but reached a plea deal to reduce the charges to a pair of traffic violations. He paid a $300 fine.
Dareus will miss Buffalo's season-opener against the Indianapolis Colts but will be allowed to participate in preseason games.
- Dan Gartland