The National Football League attempted on Tuesday to dismiss more than 200 cases brought by nearly 4,200 retired players who said they were not warned of the dangers of head trauma.
U.S. District Court Judge Anita Brody delayed a ruling on the request. "I will rule when I sort this out for myself," she said before adjourning the packed courtroom.
The class-action lawsuit could determine the league's role in caring for players with football-related neurodegenerative diseases.
The players accuse the NFL of "deliberately and fraudulently" concealing the dangers of head trauma, and are seeking damages, treatment and medical monitoring for neurological injuries they sustained during their careers.
The suit alleges the league didn't do enough to warn players that they risked permanent brain damage if they played too soon after a concussion and that it hid evidence about the risks for decades.
Brody listened intently and asked a series of questions of both camps' high-profile representation during the hearing.
Paul Clement, former U.S. solicitor general during the George W. Bush administration, represented the NFL. David Frederick, who has argued a number of Supreme Court cases, spoke for the retired player plaintiffs.
High profile attorney Ted Wells, who's represented former Dick Cheney adviser I. Lewis "Scooter" Libby, among others, was observing Tuesday's arguments. Wells is one of the lead trial attorneys who will be representing the NFL should this case go to trial.
The collective bargaining agreements players signed with their respective teams also apply to the NFL, Clement argued, adding that players receive benefits.
"This is an unusual industry," Clement said, adding that unlike most corporations, the union, clubs and league "are worried about players."
"This is a case about workplace safety," he added.
In contrast, Frederick argued passionately that the NFL does not have immunity in all cases, especially those players who played while collectively bargaining agreements were in limbo from 1987 to 1993.
Moreover, the NFL actively concealed the risks associated with repetitive impacts to the head, he said.
The league didn't do anything about the injuries because they "didn't cause bleeding or broken bones," he said. "The NFL had held itself out to be the guarantor of safety. ... When the NFL began to glorify and monetize violence on the field, its breached its duty of due care."
Last April, Alex Karras, the former Detroit Lions standout who starred in the 1980s sitcom "Webster," joined hundreds of former NFL players suing the league over concussion-related injuries.
Karras, who also played the horse-punching Mongo in the 1974 movie "Blazing Saddles," served as lead plaintiff for what was then the 12th concussion-related complaint filed against the NFL by the Locks Law Firm in Philadelphia.
Since then, the suits have been consolidated. He died in October following a battle with dementia, kidney disease, heart disease and stomach cancer.
The suits claim that plaintiffs suffer from neurological problems after sustaining traumatic impacts to the head.
Karras, for instance, "sustained repetitive traumatic impacts to his head and/or concussions on multiple occasions" during his NFL career, and "suffers from various neurological conditions and symptoms related to the multiple head traumas," according to the suit, filed before his death.
Last year, Karras' wife and "Webster" co-star Susan Clark said his dementia "prevents him from doing everyday activities, such as driving, cooking, sports fishing, reading books and going to big events or traveling."
"His constant complaint is dizziness -- the result of multiple concussions," she said in a statement. "What Alex wants is for the game of football to be made safer and allow players and their families to enjoy a healthier, happier retirement."
Critics say players traded the risk of injury for gridiron glory, while the NFL asserts there's a shared risk in playing football.
Former running back Dorsey Levens said Tuesday he knows a thing or two about "having my bell rung."
"We didn't know better. It's plain and simple," said Levens, who played for Green Bay and Philadelphia. "We knew there'd be some aches and pains, some joints and some ligaments, that may be damaged, and we signed up for that, fine. ... Not being able to remember, I didn't sign up for that."
NFL spokesman Greg Aiello told CNN at the time the suits were filed that, "any allegation that the NFL intentionally sought to mislead players has no merit."