“I’m not being paid, and I don’t need the money,” said Mr. Willis, who played for the Bengals, the Oilers and the Broncos. “This is not going to stop me from helping my brothers, and they know where I am coming from.”

The judge, Anita B. Brody, also approved a notice that warned players about companies that, according to Mr. Seeger, offer to help players “navigate what are falsely portrayed as complicated registration, medical testing and claims procedures.”

Most of the claim-service providers require players to agree to share 15 percent or more of anything they receive in return for helping them with a process that the providers portray, in stark terms, as unduly complicated. They also do not always tell players that they can call court-appointed experts to receive free advice on how to file a claim, or that they can visit doctors who will provide a free neurological exam.

Some lawyers have hosted dinners for former players at steakhouses to get them to sign up. Others have promised to get players appointments with doctors who will write diagnoses that make their medical conditions look worse than they are, according to players who have received pitches from some of the companies.

Some lawyers have also hired former players to sign up their brethren, yet do not always disclose that the ex-players are being paid to recruit other retirees. One firm hired Joe Pisarcik, the former Giants quarterback who until recently ran the N.F.L. Alumni Association, as a pitchman. (Mr. Pisarcik did not answer telephone messages left for him.)

Mr. Seeger said a few hundred of the approximately 20,000 players who are eligible appeared to have signed up for these services. But some retirees have resisted the come-ons. Walter Carter, who played defensive end for the Raiders and the Buccaneers, as well as in the U.S.F.L., has heard from at least a dozen companies pitching services.