"It stands in contrast to the league's actions to better protect players and advance the science and medical understanding of the management and treatment of concussions," Aiello wrote in an e-mail. "The NFL has long made player safety a priority and continues to do so."
But, said players' attorney Gene Locks at the time, "(the NFL) had knowledge they didn't share with the players and didn't add the knowledge to the playing rules to protect players from head injuries. What we want is for the league to stand up and be counted, and examine everyone and provide medical benefits to everyone."
In recent years, the NFL has attempted to strengthen rules that govern player conduct on the field, adding sideline medical staff -- unaffiliated with the teams -- in an effort to more independently evaluate injured players.
In 2005, the league banned the practice of tackling a player by grabbing his shoulder pads, a move commonly referred to as a "horse-collar" tackle, after concluding it commonly resulted in injury.
It also recently strengthened a 1979 rule that prohibits players from using their helmets to butt, or "spear" players during a tackle -- a rule that critics had often complained lacked official enforcement.
Players such as Pittsburgh Steelers linebacker James Harrison have since faced hefty and repeated fines for helmet-first tackles.
Others have called for added protections, however, following a series of high-profile incidents involving former players' health.
In May 2011, scientists announced that an autopsy of the brain of former Chicago Bears safety David Duerson, 50, who died from a self-inflicted gunshot wound, showed evidence of "moderately advanced" chronic traumatic encephalopathy, or CTE.
NFL linebacker Junior Seau -- who also took his own life last May -- suffered from a neurodegenerative brain disease that can develop from concussions known as chronic traumatic encephalopathy or CTE.
CTE is a degenerative, dementia-like brain disease linked to repeated brain trauma. The disease has been found in the brains of 33 of 34 former NFL players, including Duerson, studied at the Boston University School of Medicine Center for the Study of Traumatic Encephalopathy as of last May. Their cases share a common thread -- repeated concussions, sub-concussive blows to the head, or both.
A brain with CTE is riddled with dense clumps of a protein called tau. Under a microscope, tau appears as brown tangles that look similar to dementia. But the cases of CTE have shown this progressive, dementia-like array in players well in advance of a typical dementia diagnosis, which typically occurs when people are in their 70s or 80s.
Several NFL players, including LaMar Campbell and Thomas Jones, have said they want to donate their brains for research upon their deaths.
So does Kevin Turner, a former fullback for Philadelphia and New England. Turner suffers from ALS, or amyotrophic lateral sclerosis, also known as Lou Gehrig's disease. Turner believes the ALS results from blows to the head he received while in the NFL. He also wants to donate his spinal cord after he dies.
Judge Brody did not indicate how long it would take for a final decision on whether or not the suit goes to trial.
But Turner said he and others can't wait too long for a ruling.