The Raiders have placed 26-year old OLB Jon Alston on the Injured Reserve List due to a severe concussion.  He played in 9 games for the Raiders this season and he had 23 tackles including 2 tackles for a loss.  In his four years with the Raiders, Alston has played in 39 games in which he has 66 tackles, 1 pass defensed and 2 forced fumbles.  This will hurt the depth of the defense and the special teams of the Raiders.