​New Orleans Saints wide receiver Chris Olave (12) runs against Atlanta Falcons linebacker Divine Deablo (0) during the first half of an NFL football game in New Orleans, Monday, Oct. 5, 2026. (AP Photo/Gerald Herbert) Gerald HerbertArizona Cardinals left tackle Jayden Williams is among a slowly growing number of NFL players who have tried wearing a Guardian Cap — a soft, protective helmet cover that the league believes could help mitigate head injuries — during games.His reasoning is simple: What’s the harm?“You go out there and bang your head on every play,” Williams said. “If I can get a little extra protection, why not have it?”It’s a common sentiment shared by some of the roughly 20 to 25 players who have opted to add the extra protection during games during the 2026 season. The hope is that wearing equipment like the Guardian Cap can make a violent game safer.But that’s part of the problem, according to Chris Nowinski, who is the CEO of the Concussion & CTE Foundation in Boston. He believes the NFL is overselling the benefits of the cap to give a false sense of comfort about a dangerous sport that can’t be completely sanitized.“It works a little bit in a lab, but the benefits have been dramatically overstated,” Nowinski said. “The one thing that needs to be clear to players is that it’s never been shown to reduce concussions, the company itself refuses to market it as reducing concussions and there’s zero reason to believe it would make a significant difference in reducing CTE rates.”The NFL’s push for the Guardian Cap comes against the backdrop of stories about former players being diagnosed with chronic traumatic encephalopathy (CTE) after death.A degenerative brain disease that has been linked to concussions and other head trauma common in military combat and contact sports, CTE has been diagnosed in more than 100 former NFL players, casting a pall over the United States’ most popular sports league.Some high-profile football players diagnosed with CTE after their deaths include Hall of Famers like linebacker Junior Seau and quarterback Ken Stabler, along with former Patriots tight end Aaron Hernandez.Does the Guardian Cap work?The NFL says that laboratory testing has shown that if one player wears a Guardian Cap, there is about a 10% to 15% reduction in forces transmitted through the helmet, and a 20% to 30% reduction if both players are wearing the cap.Once the league had those numbers, it mandated the caps at contact practices for most players since 2022. Quarterbacks, kickers and punters are the only position groups not required to wear the caps during practices that involve contact.Dr. Allen Sills, the NFL’s chief medical officer, disputed the league is making unfounded promises about the effectiveness of the caps. He called it “a tool in our toolbox” to combat head injuries — not a panacea.“We actually did not introduce the Guardian Cap to reduce concussions, that was not our intentio