NEW YORK — The NFL announced Friday that it will allow players to wear protective soft-shell helmet covers known as Guardian caps during games next season if they choose. The league also is expanding the use of the devices during practices. Defensive backs and receivers have joined the position groups now required to wear the caps during all contact practices. The NFL has mandated the caps’ use at practices for some players since 2022. Quarterbacks, kickers and punters are the only remaining position groups not required to wear them during practice. No players will be required to wear the caps during games, but they now have the option to do so. “We’ve got two years of data now showing significant concussion reductions in those players that wear Guardian Caps in the NFL,” Dr. Allen Sills, the league’s chief medical officer, said during a recent webinar discussion. According to NFL data, the cap will absorb at least 10% of the force during a hit to the helmet. That doubles to 20% if both players involved in the hit are using the caps. The league said concussions reached a seven-year low during training camp last year, when use of the caps was mandated for some players. The caps are manufactured by Guardian Sports, based in Peachtree Corner, Ga., an Atlanta suburb. Photos: Why the Chicago Bears wear padded helmets