The NFL has required all linemen, linebackers and tight ends to wear Guardian Caps, the soft-shell helmet covers, for part of training camp since last year.

This year, the safety measures have expanded to include running backs through all of preseason and regular-season contact practices. 

NFL executive Jeff Miller has hinted that the Caps could someday be worn in actual games.

"I think the day could come," Miller, who oversees NFL player health and safety, told Good Morning Football. "But at the same time, a lot of the helmets are also making advances, too, and so some of the protective benefits you get from the Guardian Cap hopefully will be seen in helmets in the next year or two."

The NFL found that players wearing the Caps in 2022 practices sustained both concussions and general impact at a significantly reduced rate.