The Guardian cap was initially mandated for early training camp practices in 2022. The league expanded the requirement last year to include regular-season practices. Quarterbacks, kickers and punters are the only positions groups exempt from wearing the caps in practice.

The Guardian cap is meant to "reduce the impact of daily blows" and NFL Commissioner Roger Goodell reported that it has produced a "50 percent reduction in concussions" for those who wore it in training camp. “And that has a carryover into the regular season. Because if they get into the regular season, and particularly later in the season healthier, that's going to ultimately lead to less injuries. So, a lot of progress, but a lot more work to do."