What is a 'hold-in'? Deebo Samuel, DK Metcalf, Derwin James among high-profile NFL players at training camp but not participating
Page 2 : When did cups become uncool?
An NFL player will stop wearing his 'Man of God' headband after the league fined him $7000
Why NFL Players Don't Wear Cups
Philadelphia Eagles Submit Proposal To Allow NFL Players To Wear No. 0 – SportsLogos.Net News
For Various Reasons, N.F.L. Players Do Not Wear Cups - The New York Times
The NFL's Last Helmetless Player Didn't Even Like Hats
Football Guardian Cap draws mixed reviews from players, experts for safety effectiveness - The Daily Tar Heel
Player-tracking system will let NFL fans go deeper than ever
Do NFL players wear cups? NFL fact-checking
More Than Just Dominant: Julio Jones Is Unlike Anything the NFL Has Seen Before, News, Scores, Highlights, Stats, and Rumors
Animal feces not all that's in NFL players' mouthguards
Why do NFL players not wear protective cups? - Quora
Flag football reaches the Pro Bowl as concussion fears stalk the gridiron, NFL