Oakland safety Jarrod Cooper was suspended on Friday for the Raiders' first four regular season games for violating the NFL's policy on steroids. Cooper, a valuable special teams player, will be allowed to participate in training camp and preseason games. But he won't be able to be on the team's active roster until Oct. 1, the day after the teams' fourth game against Miami. Cooper is the second Raiders player to be suspended for violating the league's substance abuse policy. Running back Dominic Rhodes was also suspended for four games.