(Renton, WA)  --  Seahawks head coach Pete Carroll has some doubt when it comes to the futures of strong safety Kam Chancellor and defensive end Cliff Avril.  Carroll said Tuesday that both players are going to have a hard time playing football again because of their neck injuries.  Avril and Chancellor suffered season-ending neck injuries a month-and-a half-apart.  Carroll also revealed in his season-ending press conference that cornerback Richard Sherman, who's recovering from a ruptured right Achilles, will have a clean-up procedure on his other ankle area.