EAST RUTHERFORD, N.J. — It was a very businesslike Miami Dolphins locker room after Sunday’s dominant 34-10 victory over the New York Jets at MetLife Stadium. 

That’s because no one was surprised by what happened on the field. The resurgent Dolphins, a team with a four-game winning streak, an emerging physical presence, a consistent running game and a big-play defense, expect to win nowadays. That type of confidence is huge, and it stems from one thing.

“Belief, man,” linebacker Jordyn Brooks said.

Their steadfast belief is now being rewarded. The The Dolphins (6-7), who remain playoff longshots despite their winning streak, seem on the verge of shocking the world.

One big key to that is that the Dolphins, after starting the season 0-3, then 1-6, and then 2-7, now believe they should win. And that type of bedrock belief has become part of the Dolphins’ newfound identity. 

“I really love this team because they’ve made the choice, the hard choice, to not only believe in themselves, but put in the work,” coach Mike McDaniel said, later adding, “they were well aware they were the only people that really believed in themselves.”

It was easy to discount the Dolphins at the start of the season. There were injuries, ugly losses, bone-headed mistakes and lots and lots of frustration. All of that is vanishing. The Dolphins are now getting healthier and playing better. It shows.

You could contend the Dolphins, due to flaws in their game, should have lost either the Washington or New Orleans games recently. You can’t say that about the Jets game. It was a complete victory.

The Dolphins rushed for a season-best 239 yards led by Jaylen Wright’s career-best 107 yards and De’Von Achane’s 92 yards before he went out with a rib injury in the second quarter.

Defensively, the Dolphins, who were 29th in the league in run defense entering the game, held the Jets, who were No. 7 in rushing offense, to 65 yards rushing. Defensive tackle Zach Sieler had 2.5 sacks. The back end of the defense produced three interceptions.

There were few signs of slippage Sunday save for the punt team, which surrendered a 78-yard punt return touchdown and allowed a first down on a fake punt.

Believing is paying dividends.

Now, it should be noted that the Dolphins are trying not to get too caught up in the hoopla of being one of the NFL’s hottest teams. They’re trying to stay level-headed and look at the big picture.

“We’re just playing ball, man,” said cornerback Rasul Douglas, who had one of Miami’s three interceptions against the Jets. “We’re all playing together, that’s all.”

And they’re getting used to winning. They’re expecting to win.

When the Dolphins defeated Buffalo a few weeks ago to start their current four-game winning streak the locker room featured a wild celebration with players racing each other in laundry carts and 60-year-old wide receivers coach Robert Prince break dancing. 

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There was none of that Sunday. There was music, a few jokes here and there, lots of smiles and even more good vibrations. But there was no carnival atmosphere.

This is very different from a few weeks ago when the Dolphins were struggling with a 2-7 record and trying to figure out how to win games. 

This Dolphins team, with its fringe status as an AFC wild-card contender, is confident. It’s aggressive. It’s ascending.

The Dolphins’ new identity as a run-first team has fostered lots of belief that they can finish the season as the team they’ve developed into the past few weeks, the team that has won five of its past six games.

The Dolphins probably aren’t headed for the playoffs. In fact, it would be a miracle if they made the postseason. But you never know what can happen if you believe.

“It’s just the mental battle, keep doing details,” right tackle Austin Jackson said. “Keep doing the right things, the little things.”

In other words, keep believing.