NFL players have been unable to secure a contract tied to the growth of the salary cap. Darrelle Revis attempted to get it into his contract in 2010 while Kirk Cousins sought a clause in his 2016 negotiations.

The NFL salary cap has grown by 37 percent since 2013.

Teams have resisted tying salary to the cap as it negates their benefit of a long-term deal.

In the NBA, maximum contracts are tied to the salary cap for the first season of the deal and then have pre-determined raises every year thereafter. When a player becomes a free agent again, they can sign for a percentage of the salary cap again depending on their years of service.

As Peter King points out, quarterbacks are making approximately the same percentage of the cap (15 percent) as they were in 1997. Brett Favre had an average salary of $6.5 million in 1997, which was 15.7 percent of the cap. In 2017, Matthew Stafford's average salary of $25.3 million represents 15.1 percent of the cap.