Cooper, who has been the Raiders' top special teams player for the past three seasons, will be forced to sit out Oakland's first four games of the regular season and won't be eligible to return until after the team's Sept. 30 game against Miami. He will be allowed to take part in training camp workouts and all preseason games, however.
Cooper is the second Raiders' player to be suspended by the league for violating the substance abuse policy. Running back Dominic Rhodes, who signed a two-year, $7.5 million contract with the team in the off season after helping lead Indianapolis to a Super Bowl title last season, was suspended on July 3. He will also miss the first four Oakland games.
Cooper's absence shouldn't have too big an effect on the Raiders. Though he played in nickel and dime packages, Oakland is deep at the safety position, having recently signed free agent Donovin Darius from Jacksonville. Darius joins Michael Huff and Stuart Schweigert, the two starters from last season.