There's been an uptick in rebellious players who have gone without their helmets in warmups, and some recent violators were the Ottawa Senators and the San Jose Sharks.
New violators were the New Jersey Devils, who took to the ice for warmups wearing hats to commemorate defenseman Brendan Dillon's 1,000th game in the NHL. The team would later lose 5-3 to the Columbus Blue Jackets.
"It is mandatory for all players who entered the NHL beginning with the 2019-2020 season or later to wear their helmet during pre-game warm-up," the subsection reads. "To be clear, all players who entered the League prior to the 2019-2020 season and who are currently playing are exempt from this mandate."
Teams have tried their best to find workarounds to skirt the rule by leaving their helmets in locker rooms, and the reasoning is understandable.
"Just to have a little bit of fun," San Jose Sharks goaltender Alex Nedeljkovic said, per The Athletic's Eric Stephens and Jesse Granger. "It's a fun city. Everyone wants to have a good time. Maybe play with a little bit of swagger. Everybody feels good with the hair flowing and all of that. I thought it was fun. Maybe we'll do it again, who knows?"