Five universities published studies since 2023 on Guardian Caps, a soft-shell padded helmet cover that slips on the plastic shell.

The NFL has not publicly addressed a study that involved its top medical official and reported the benefits of Guardian Caps are 'uncertain.' ...

It's become more common in recent years to see NFL players wearing Guardian Caps on the field. Here's how they work.

That's how the salary cap comes into play during the trade deadline. Teams with more cap space could be better poised to take on a higher-priced trade target. So who has the most cap space in the NFL ...