The NFLPA is threatening to file a grievance if the NFL refuses to institute a system to verify the credentials of all medical personnel on the 32 teams. 

DeMaurice Smith mentioned three amendments the NFLPA wants to make to the new CBA, including the appointment of "a neutral chief safety officer who can hear appeals about acceptable levels of medical care."

The union has been pressing the NFL to put independent neurological consultants on sidelines during games to help diagnose and treat concussions, something league general counsel Jeff Pash announced at a news conference earlier Thursday he expects to begin next season.