Every year as training camp concludes, teams prepare to pare down their rosters for the start of the regular season. If you stop and examine the team, you can see the guys that are the long-term fixtures with the franchise, and others who are really auditioning for the following season elsewhere in the league.
How, you may ask?
Notice what players the team lets go into the season without a new deal, or at least starting the discussions for a new deal. I call this the Martellus Bennett effect. You know the guy that is holding the roster space, but in no way does the team want to spend the money required to keep him around any longer than his current deal.
The players I am talking about are those that have either failed to meet the expectations of where they were drafted, or are too injury-prone to warrant a big investment in their future. Often the teams take the approach that they cannot do better right now, but hope to upgrade that position next year with a more reliable player.