Agree with 77. Also don’t forget you need player salary for your draft picks (only between 8-27k depending on level) but if you tap out your player payroll you will feel foolish not being able to pay your picks.
also, sometimes it’s strategy to keep 6-8 million in player payroll. If you are in win now mode you can get a better trade for a vet by being able to take on salary. If you are rebuilding you can take on a bad contract plus a prospect if you have the money. All depends.