Nashville Predators defenseman Roman Josi had plugged his phone in for a charge when he noticed texts coming in at a rapid rate.

He went to check out what in the world was happening when he discovered the news: Shea Weber had been traded to the Canadiens for P.K. Subban.

Like everyone else, the initial feeling was absolute shock. But for Josi, what followed was a feeling of sadness. Weber was part mentor, part protector, part coach, but mostly just a really good friend.

The defenseman now headed to Montreal had raised the next generation of Predators defensemen. It’s easy to play with confidence as a young defenseman when Weber is by your side.

Mattias Ekholm put it this way: “Even though he had his contract, he was the captain, he had pretty much everything you could ask for as an NHL player -- still, every practice, every game he’s the first guy on the ice, playing as hard as ever, every time he hit the ice.”

That left an impression on Nashville's young defensemen, and the Predators are better off because of it.

But once the sadness left, another emotion surfaced: excitement.

“We’re excited to have P.K.,” Josi said.

The emotional stages in the aftermath of the Weber-for-Subban swap have concluded in Nashville, and what remains now is a defense that is built unlike just about any other in the NHL.

GM David Poile has gone all-in on the notion that a successful NHL defense is all about skating, puck moving and an ability to generate offense. A top four of Subban, Josi, Ryan Ellis and Ekholm is one full of offensive ability and strong skaters.

It doesn’t include a guy who traditionally is clearing the crease or bringing the fear of God into opposing forwards who dare go near Pekka Rinne. That guy might not be necessary because, with the current defensive group pushing play, the opposition may never have the puck.

“The game has changed and you’ve got to change with the game,” Poile said. “We’re all trying to anticipate and create how to be successful in the game. I’ve been in the game a long time, we come from the days of the Flyers winning the Stanley Cup when physicality outweighed the skill. Now, 40 years later, you’re watching a team like the North American team with their speed taking on the best teams and players in the world and holding their own.”

It’s amazing how that glimpse of a team built purely on speed and skill has impacted general managers. They definitely took notice. It was like watching game theory play out in real life.

On some level, the Predators are doing the same thing with their defense. The traditional blueprint in the NHL has been to pair a puck-mover with a stay-at-home defenseman. Kings GM Dean Lombardi recently won two Stanley Cups subscribing to that theory.

But even since Los Angeles won that first one in 2012, the game has changed. The Predators have been ahead of the curve, but still felt it was necessary to keep a guy like Barret Jackman around last season to do some of the traditional duties of the stay-at-home defenseman.

Now, he’s gone.

In his place is Yannick Weber, a good skater who is known more for pitching in on the power play than clearing bodies anywhere on the ice.

It’s been years since the NHL changed the rules that first started to eliminate the big, slow defensemen. But Poile has noticed the evolution speeding up the last few seasons.

With fighting being essentially eliminated, fourth lines are full of skill. The young players enter the game faster than ever.

“Ice time is different than it was five years ago. The third pair and fourth line never played more than 10 minutes, often much less,” Poile said. “Now, virtually every fourth line gets at least 10 minutes. That speaks to the speed.”

We saw it play out in the Stanley Cup finals this past spring. The Penguins were loaded with speed up front and had a defense full of players capable of quickly retrieving the puck and getting it to their forwards with speed.

The Sharks did fine when Brent Burns, Paul Martin and Marc-Edouard Vlasic were on the ice. But man, did things get dicey when Brenden Dillon and Roman Polak took a shift.

“You need someone to kill penalties, some size and physicality,” Poile said. “You can’t win with 20 players the same.”

It’s all about finding the right balance, and it’s skewing more and more towards offensive skill.

Last season, Ekholm played mostly with Ryan Ellis, and when the two were on the ice, they controlled 56.2 percent of the even-strength shot attempts. They have a skill set that works well together, with Ekholm articulating quite well why he’d always rather be paired with a defenseman with offensive tendencies.

“If I make a good play down low and win the puck and skate the puck up the ice, I want my partner being on the way up the ice too,” Ekholm explained. “That makes it easier, it’s another option. Instead of having a stay-at-home guy, staying in front of the net, and just taking care -- then you don’t create that odd-man [rush]. If I win my battle, and he’s not joining, his guy is going to come to me and it’s still a 4-on-4. That’s the way we want to play.”

Considering how well Ekholm and Ellis played together, that leaves the possibility that we’ll see a pair of Josi and Subban.

Josi is one of the reasons that Europe is still playing in the World Cup, with tonight’s possible elimination game against Canada his last chance to keep those championship hopes alive. He’s done it because he’s given that Europe defense the kind of elite skater necessarily to play with the best countries in the world.

Pair him with Subban and it’s a matchup nightmare for opposing teams. It’s the equivalent of having a top pair of Erik Karlsson and Kris Letang. It’s ridiculous.

Ekholm had been focused on playing in the World Cup for Sweden, but even in the middle of that, he paused a second to think of what a Subban and Josi pair might look like.

“I can’t say it hasn’t crossed my mind,” Ekholm said. “We have a solid top four defense corps right now. Anyone can play with anyone. ... For me, it doesn’t really matter who is playing with whom. Everyone is skilled and has that hockey sense and hockey mind. You can just go out and play with whoever you play with.”

That’s exactly how it was designed.