The NFL is a league of constant change. Only a select few players have any kind of job security; everyone else is fighting to keep his job every single year.
As an influx of young talent bursts onto the scene, older veterans must prove that they are still effective and worth paying a little extra to have around.
However, teams are always looking to get younger, and the faster you can insert younger players into the starting lineup, the faster they can develop.
Here's the best rookie vs. veteran battle on every roster.