caption: FILE - In this Tuesday, Jan. 29, 2019 file photo, NFL Chief Medical Officer Dr. <PERSON> explains what takes place inside a sideline injury tent, right, during a health and safety tour at Mercedes-Benz Stadium for the NFL Super Bowl 53 football game in Atlanta. Everyone who has watched an NFL player disappear into that medical tent on a sideline has an idea of what happens once the flap folds down. The NFL shares a look Tuesday, Jan. 28, 2020 inside the tent and game-day procedures designed to help when someone is hurt. (AP Photo/ <PERSON>, File)