Rex Ryan's Buffalo Bills defense is undergoing yet another shake-up this offseason after he abruptly fired defensive line coach Karl Dunbar on Sunday. The move came as a significant surprise because Dunbar spent the past four years working for Ryan, and because most teams' coaching staffs are already set by mid-March. ''This was a difficult decision as Karl both played for me and then coached on my staff,'' Ryan said, in a statement released by the team. More...