ESPN told viewers that players were given five minutes to warm up after Hamlin was taken off the field. The N.F.L. denied that. On Sunday, Commissioner Roger Goodell addressed the question.
The league and the union said the concussion protocol was followed after Dolphins quarterback Tua Tagovailoa hit his head two weeks ago. But his return to that game has prompted a change in the protocol.
Physicians assessing head injuries at N.F.L. games are expected to be able to diagnose concussions. But recent injuries to Tua Tagovailoa raised questions about how effective the doctors can be.
After Miami Dolphins quarterback Tua Tagovailoa sustained two head injuries in the last week, the players’ union removed a neurologist who was part of the process that allowed him to return to the field.
The group’s executive director, DeMaurice Smith, was nearly ousted from the role after negotiating a contentious 2020 labor deal. Candidates are lining up to replace him as soon as next year.