The family of former Chicago Bear Dave Duerson filed suit against the NFL, alleging the league concealed information on on-field concussions. The family of Duerson, who committed suicide last year after being diagnosed with progressive, advanced brain damage known as chronic traumatic encephalopathy, allege the NFL had information concussions from playing football could lead to brain damage but did not inform players and coaches, the Chicago Tribune reported Friday. Duerson suffered at least three concussions during his 11 years in the NFL. \"If the NFL would have taken the necessary steps to oversee and protect Dave Duerson by warning him of the dangers of head traumas ... then (he) would not have suffered dangerous repetitive head trauma, would have recovered more rapidly and would not have sustained permanent damage to his brain which contributed to cause his death,\" Thursday\'s filing by the family states. Thomas Demetrio, a lawyer for the family, said other NFL players should take warning from Duerson\'s case. \"Current coaches, trainers and players from the NFL down to the peewee level need to take heed -- avoid concussions as best they can, recognize their significance and, when in doubt, sit out,\" Demetrio said. \"And by all means, don\'t simply say \'my toe hurts\' when it\'s really your head.\" NFL spokesman Greg Aiello said he could not comment on the lawsuit as he had not yet seen it.