Nearly two dozen former NFL players are suing the league over severe and permanent brain damage they say is linked to concussions suffered on the job.
The complaint, the latest in a series of recent lawsuits against the league, was filed on behalf of former Miami Dolphins teammates Patrick Surtain, Oronde Gadsden and 19 other players.
They are accusing the NFL of deliberately omitting or concealing years of evidence linking concussions to long-term neurological problems.
The NFL has denied the charges and say player safety has long been a priority.
The players claim the NFL misrepresented the seriousness of their injuries "with the intent of inducing NFL players, including Plaintiffs, to return to play as soon as physically possible after having suffered a football-related concussion and to promote an aggressive style of football that would attract viewers".
According to the lawsuit, following numerous studies on the risks of concussions, the NFL created a committee of researchers and doctors in 1994 to study concussions. The committee was supposed to be independent, but members were affiliated with NFL, the lawsuit said, and the group did not include a doctor specialising in neurology or other brain research.
The players are seeking a jury trial and unspecified damages.
