Judge Anita Brody of the United District Court for the Eastern District Court of Pennsylvania rejected the proposed $765 million settlement "between the N.F.L. and more than 4,500 retired players who sued the league and accused it of hiding the dangers of concussions has raised significant questions about whether there will be enough money for all of the payouts, medical tests and treatment," The New York Times reported.

"I am primarily concerned that not all retired N.F.L. football players who ultimately receive a qualifying diagnosis or their related claimants will be paid. Unfortunately, no such analyses were provided to me in support of the plaintiffs' motion. In the absence of additional supporting evidence, I have concerns about the fairness, reasonableness and adequacy of the settlement," Brody wrote in the ruling.

The judge's ruling "will probably force the plaintiffs' lawyers and the N.F.L. to provide documents proving there will be enough money to pay for the retired players' claims," as reported by The New York Times.

"We respect Judge Brody's request for additional information as a step towards preliminary approval," the N.F.L. said in a statement. "We will work with the plaintiffs' attorneys to supply that information promptly to the court and special master."

The "rejection of the proposed settlement is a sign that the judge recognizes the importance of the case, which has received global attention and will probably provide a framework for the settlement of other concussion-related lawsuits, including those brought by former N.H.L. players against the N.H.L. and by former college football players against the N.C.A.A," The New York Times also reported.

"The judge understands that it's controversial. Over the last five years, appeals courts have scrutinized class-action settlements, especially in the Third Circuit, where she sits. Given that this is going to draw objections, she's doing the right thing in saying, We can't just take your word for it," said Ted Frank, the president of the Center for Class Action Fairness, a nonprofit public interest law firm.

The NFL Playoffs are in high gear, as two championship games are slated this week, with the winners going on to Super Bowl XLVIII. The Denver Broncos, led by Peyton Manning face the New England Patriots in the AFC Championship Game, while the San Francisco 49ers are pitted against the Seattle Seahawks.