With Guardian Caps being legal to wear in-game for the first time this season, Pittsburgh Steelers OG James Daniels has worn one in every game dating back to the preseason. In Week 1, Daniels was one of just five players to wear a guardian cap, along with Indianapolis Colts TE Kylen Granson, Colts S Rodney Thomas, Tennessee Titans TE Josh Whyle and New England Patriots S Jabril Peppers, per Austin Gayle of The Ringer.
A Guardian Cap is a soft-shell helmet intended to reduce head trauma and ideally reduce concussions, although the main intent is to reduce the trauma involved with repeated minor blows to a head that NFL players endure on a weekly basis.