Football is a cutthroat business. Poor performances are rarely tolerated, and general managers are quick to offload expensive contracts attached to disappointing players.
At this time of year, the free-agency gold rush and the draft dominate the agenda in NFL front offices. Clearing cap space to make future roster moves begins now, and a number of players will face a nervous few weeks in the knowledge that they are on the hot seat.
Not all the players on this list will be traded or released, but all of them have one thing in common: They need to deliver for their teams, fast.
Let me take you through the top 20 players who stood in the way of their team's success in 2011.