The N.F.L."s Lingering Concussion Problem Thearon W. Henderson/Getty Images Michael Griffin of the Tennessee Titans, left, was penalized for a helmet-to-helmet hit on November 24. When the N.F.L. agreed in August to pay $765 million to settle hundreds of cases accusing it of hiding information about the dangers of concussions, the league no doubt hoped that fans would instead focus on the players and the games that make the sport a national obsession. To some extent, that has happened. Television ratings have hit new highs, attendance and merchandise sales remain strong, and the league is gearing up for its first Super Bowl outdoors in a cold climate. Yet the drumbeat of news about concussions, head hits and cognitive disorders continues unabated. Barely a week goes by without a star player being sidelined with a concussion. Video clips of helmet-to-helmet collisions in slow motion are a staple of game broadcasts, and concussions are also in the spotlight off the field as former stars like Tony Dorsett speak publicly about their memory loss, irritability and other health problems. While the N.F.L. and the lawyers for the former players who sued the league are still haggling over the finer points of their deal, a growing number of retirees are hinting they will vote against it. This month, the former star quarterback Craig Morton sued the N.F.L. in federal court, making some of the same allegations as those from the more than 4,500 retired players who sued the league during the past few years. Morton's filing suggested that he would reject the settlement and continue pursuing a separate case against the league. Dozens, if not hundreds, of former players could join him. Morton's lawyers accused the league of agreeing to a deal just before the season as a way to deflect negative attention. "Their concerns are different from the P.R. concerns of the league," Jon King, one of Morton's lawyers, said of the former players. Several former Kansas City Chiefs have taken a new tactic: they sued the team in state court in Missouri, saying that they have been unable to file workers" compensation claims. Former college players are still fighting the N.C.A.A. and, in a new development, nearly a dozen retired hockey players have sued the N.H.L. over head injuries. All of this suggests that while the N.F.L. may have addressed its biggest legal challenge, many smaller ones endure. And as long as concussions are in the national conversation, young athletes and their parents will have to consider whether the game is safe enough to play.