The restricted free agent has become a dying breed ever since the new Collective Bargaining Agreement was installed, which made rookie contracts for players beyond the first round all four-year contracts. Previously, players beyond the first round were typically given three-year contracts, making them restricted free agents in the year that followed.
Thus, most players no longer see restricted free agency. Basically, it requires that you spend some time off of a 53-man roster or on no roster at some point. The Pittsburgh Steelers’ two restricted free agents this year serve as a good example of the remaining players who actually reach that point, and it will be interesting to see if they find any market.