Also he has an agent who takes 10% off the top, and probably other staff like lawyers and accountants to pay. But the main point holds. He has saved his net salary, and lived off his non-playing income.
But it would be nice for people to see how much Uncle Sam takes.
The NFLPA limits an agent's take to 3% max or he can be decertified as a agent by the Union. If he uses the same person for non NFL-related revenue streams the rep's pay is whatever they agree to.