Jonathan Taylor among the few NFL players to wear the 'guardian cap' on his helmet

The NFL has been using the guardian cap during training camp practices for a while. You've likely seen them in photos.

It's a huge pad that goes over the regular football helmet, and it is designed to prevent concussions. This season for the first time, the NFL allowed players the option to wear the guardian caps during games.

Not many players took the league up on the offer but one star did: Indianapolis Colts running back Jonathan Taylor.

Taylor was wearing the cap during Sunday's preseason game against the Denver Broncos. It does look odd when the camera zooms in, with a cover featuring the Colts logo stretched over it.

It's not a huge distraction otherwise, and it's a positive if it prevents concussions. Colts tight end Kylen Granson was another player to wear the cap during the first week of the preseason.

Pittsburgh Steelers offensive lineman James Daniels wore it on Saturday. He was believed to be the first to do so.

"My head doesn't hurt, so that's good," Daniels said after the game, via Brian Batko of the Pittsburgh Post-Gazette. "Hopefully more and more people start wearing them."

It doesn't look fashionable and it's out of the norm, which is why you didn't see many players wearing them in the first week of the preseason. Perhaps it will be more common with players like Taylor trying them out. It's another thing for NFL fans to get used to this season.