NFL commissioner Roger Goodell speaks during a news conference in...

NFL commissioner Roger Goodell speaks during a news conference in advance of Super Bowl LII, Wednesday, Jan. 31, 2018, in Minneapolis. Credit: AP / Matt Slocum

The announcement of the rules change came late in the day, long after the NFL had announced the new guidelines for what constitutes a catch and nearly overlooked amid all the speculation about a potential trade of Giants star receiver Odell Beckham Jr.

But make no mistake: The message delivered Tuesday afternoon has the potential to fundamentally change the way pro football is played from now on.

League owners unanimously approved a rule that strictly prohibits any player at any time from lowering his helmet to initiate contact with an opponent. Offensive players, defensive players, special teamers — everyone is now subject to a new restriction aimed to reduce the number of helmet-to-helmet hits and thus drive down the concussion rate. If you lower your head to initiate and make contact with your helmet, a 15-yard penalty will be called, and you are subject to being ejected from the game.

Within minutes of the rule’s unveiling, many current players around the league immediately expressed shock — and some anger. Defensive stars such as Richard Sherman and Josh Norman, as well as former Giants defensive end Justin Tuck, ripped the change.

“It’s ridiculous,” Sherman told USA Today. “Like telling a driver if you touch the lane lines, you’re getting a ticket.”

Tuck tweeted, “I’ll join the group of current and former NFL players to say that I think this new rule is horrible.”

When I asked Tuck to list specific reasons for his criticism, he tweeted, “Bob I don’t feel like typing that much.”

Safety D.J. Swearinger was livid after hearing about the new rule. “Obviously Not Football ANYMORE! THE GAME WE LOVE IS GETTING DESTROYED EVERY DAY,” he tweeted.

Clearly, defensive players are worried that they will have to fundamentally adjust their tackling technique and potentially lose their effectiveness by having to worry about not lowering their heads. For many players, it’s almost second nature to go in head first, even though they risk concussion issues or worse. Steelers linebacker Ryan Shazier suffered initial paralysis when he made a head-first tackle in a game last season.

Running backs must also be mindful of changing their technique. While lowering the helmet to initiate contact down the field was recently banned, ballcarriers were still permitted to use their helmets inside the tackle box. But even that loophole has been closed.

How the rule is implemented and officiated will be one of the most closely watched story lines, and players will be anxious to know precisely what is expected of them as the league attempts to deal with its biggest challenge. The league continues to deal with a high incidence of head trauma, and “taking the head out of the game” has become a mantra of the NFL.

Commissioner Roger Goodell bristled when I asked him Wednesday whether the sport will undergo transformational change as a result of the new rule, and cautioned skeptics not to go too far in wondering if pro football might never be the same.

“Our intent is to make sure we go to each team and we have [game] tape, we have all the analysis and work that’s been done to communicate that to [the players],” Goodell said. “I’d give them the opportunity first to understand what it is before we make a lot of judgments about the ramifications.”

Bottom line for Goodell: “We think this is going to take the helmet out of the game, and get [helmets] to be protective devices, as opposed to something that can be used as a weapon.”

Goodell said there was unanimous support among the owners and coaches to make the change, although some coaches privately expressed concern about how the rule will be officiated and how quickly players can make the adjustments. One general manager also said it is possible that ejections and/or suspensions related to the new rule might not take place immediately so players can get used to the rule.

Saints coach Sean Payton, a member of the competition committee, is on board with the change.

“I think we’ll see it have a great effect on one element of this helmet [issue] in how we want the game to be played,” Payton said. “I think you’ll still see the physicality.”

The key now is communicating to the players what is expected of them. And by the end of that process, over the next several weeks, competition committee chairman Rich McKay believes the majority of players will understand the rule and be in favor of it.

“We understand it’s a major change, and we take the responsibility,” McKay said. “We need the coaches locking arms with us in the teaching of this, and we’ve got to work together. We’ve got to put the materials together, we’ve got to show the tape. We have to make sure all of you [in the media] see it, and it’s taught the same way at all 32 [teams].”

McKay is confident the change will work, and not just at the NFL level. He believes once the players become accustomed to not using their helmets to initiate contact, the habits will spread to the colleges, high schools and youth leagues.

“I think the players, who are the best athletes in the world, will conform and hopefully this becomes the springboard to take it all the way down at all levels,” he said. “The head and the lowering of the head has become too commonplace, and it needs to get out of the game.”

No argument on that last point.

Now it’s up to the league to make certain the players understand what’s expected of them and that they can adjust their technique and thus make the game safer without sacrificing the fundamental appeal of the sport.