Bobby Douglas, a former NFL quarterback, and John Cornell, a former Northwestern player, charge the league and the helmet maker didn't do enough to inform players about the risks of the body-contact sport, the Chicago Tribune reported Wednesday.
William Gibbs, an attorney for the men who filed the suit Monday in Cook County Circuit Court, said the legal action "seeks to hold the league responsible for its conduct in failing to address the real, significant issue of concussive brain trauma."
Douglas, 66, played for the Chicago Bears from 1969 to 1975 and went on to play for the San Diego Chargers, New Orleans Saints and Green Bay Packers. Cornell, 66, attended two training camps for the Saints.
The men claim they received multiple concussions and subconcussive brain injuries that have put them at risk of brain damage and chronic traumatic encephalopathy, a degenerative brain disease.
The lawsuit claims the league knew of the health hazards of concussions but told players there was no evidence they were linked to long-term brain damage. The suit also claims Riddell was negligent by failing to tell players their helmets wouldn't protect them from concussions.
The NFL and Riddell declined comment on the lawsuit.
Gibbs said the suit could be incorporated into a lawsuit filed against the NFL by more than 4,500 former players. The league agreed in August to pay $765 million plus legal fees to settle the suit but admitted no wrongdoing.