Seahawks RB Chris Carson is retiring from the NFL, per insider Ian Rapoport. According to Rapoport, Seattle will officially release him with a failed physical designation. It’s not a surprise, as Carson’s been sidelined with a neck injury since Week 4 of last season. His career ends with 769 carries for 3,502 yards and 24 TDs. Seattle moves forward with a 1-2 punch of Rashaad Penny and Kenneth Walker.