With star defensive tackle Kyle Williams set to miss another game or two and second-year nose guard Torell Troup ailing, the Buffalo Bills suddenly have a major depth issue along their defensive line.
Buffalo entered the regular season with seven defensive linemen on the roster, but they were playing one of them - Alex Carrington - at outside linebacker, rather than his typical defensive end position. Carrington has since reverted to end, but he was replaced at outside linebacker by veteran Spencer Johnson. As such, the Bills have only listed six players as defensive linemen for most of the season.
Buffalo's base defense uses three defensive linemen, and their nickel sub-packages typically use two of them, with outside linebackers becoming the pass-rushing defensive ends in those looks. Marcell Dareus - who is having a solid rookie season, and is one of just four players to record a sack this year - and Dwan Edwards get a lot of playing time. Beyond them are Carrington and Kellen Heard. All four of these players have had their moments, but let's face it - they're not a healthy Williams.
Bills GM Buddy Nix built this defense from the line backwards - but injuries and ineffectiveness at other positions (like outside linebacker) have depleted the potential effect of that plan. Buffalo has been getting good play from these players, but haven't made many improvements defensively as a result.