Wes Walz calls it the “goofy gear.”

Walz, the former Wild center whose job included playing against the other team’s most explosive lines, had that high-end, top-speed ability.

“I don’t mention the goofy gear very often,” Walz said while watching a Wild practice. “But he’s got it.”

Walz was talking about Erik Haula who, over the last half of the season, might have been the Wild’s most consistent player, using speed to slow down high-scoring lines. Haula, who is battling an undisclosed injury that has caused him to miss practices leading to Thursday’s playoff opener in Dallas, is expected to be a crucial player in the series. His line, with wingers Nino Niederreiter and Jason Pominville, will play against Dallas’s top six forwards — including Jamie Benn, Tyler Seguin and Jason Spezza — and could go a long way toward deciding the series.

Haula’s ability to hit top speed — as interim coach John Torchetti says, revving up — is key. It enables Haula to play strong in his own end, then pounce on an opportunity going the other way.

“You can’t use the goofy gear all the time, because then you don’t surprise anyone,” Walz said. “But, defensively, when you stay underneath the puck in your own zone, and you have the kind of speed Erik has, you don’t have to cheat. Because of that, you’re actually in better position to come up with more loose pucks.”

Haula set career highs in games played (76), goals (14), assists (20) and points (34) this season. His plus-21 rating tied for second-best in franchise history. He tied a franchise record with a 10-game points streak and amassed 23 points over the final 30 games.

But the thing Haula is most proud of can’t be quantified in numbers.

“It’s being able to re-establish myself as a player in this league,” Haula said. “That was my main goal when the season started.”

New outlook

Shortly after he took over for a fired Mike Yeo, Torchetti took Haula aside for a talk after practice.

“I thought before I got here he was having success,” Torchetti said. “I wanted to keep building on it. And let him know he’s going to get more ice time. I wanted to make sure he understood that. That he’d be responsible with that, and take advantage of that.”

Haula had been waiting to hear such words.

“He was real positive with me,” Haula said. “He told me he believed in me as a player. That he trusted I can do a good job and be a part of this team in an important way. It was a great, great start.”

It wasn’t always that way.

A native of Finland who starred for the University of Minnesota, Haula signed an entry-level contract with the Wild days after his 2012-13 Gophers season ended. He was shipped to the team’s AHL affiliate in Houston, coached by Torchetti.

“He was way different,” Torchetti said. “He had a lot of 1-on-1 in his game coming out of college.”

Unhappy with Haula’s defense, Torchetti sat him for a game only to get a call from Wild management. “They were like, ‘Play this kid a lot,’ ” Torchetti said. “And I said, ‘He’s got to earn his minutes.’ ”

Ups and downs

After splitting time between the minors and the Wild in 2013-14, Haula broke through in the 2014 playoffs. Flashing his speed, he had three goals and two assists in six games in a second-round loss to Chicago.

But the only way to describe last season was disappointing. Or worse.

“Disappointment is an understatement,” he said. “I only played in two of the 11 playoff games. It was a tough year.”

His troubles started after the 2014 playoffs, when he joined Finland at the world championships. His jaw was broken by an Evgeni Malkin cross-check in the gold medal loss to Russia. Then early in the 2014-15 season, Haula was hit in the head by the Rangers’ John Moore, who was suspended for five games. Haula missed only two, but he never rediscovered his game that season.

“Last year was tough,” he said. “I never became that player I wanted to be. And it was hard. Really, really hard.

“I don’t know why. A bunch of things. It’s opportunity, taking advantage of that opportunity. Being consistent in your play. I think I’ve gotten a lot better at all of that.”

For a season and a half, he was in and out of Yeo’s good graces before a turnaround. Haula had five points and was a plus-4 in January. He had 11 points and was a plus-6 in February, 12 points and a plus-9 in March.

He accepted his role as a checking center, and was doing it consistently well. When Torchetti took over, Haula’s role grew.

“Whatever your role is, you have to take pride in it as a player,’’ Haula said. “Maybe it’s power play, or being a penalty killer. If your job is to shut down someone, take pride in that.”

The challenge

Now all Haula and his linemates have to do is slow down one of the league’s most high-flying teams.

“He’s going to be asked to do more,” Torchetti said. “And he’s going to be seeing bigger guys. So you have to be ready for battle.”

Niederreiter and Pominville are big parts of the equation. Niederreiter is so strong on the puck that the line often is able to maintain a cycle in the offensive end, keeping the other team’s big scorers a rink away from the Wild goal.

Torchetti also will have defensemen Ryan Suter and Jared Spurgeon on the ice against the most talented opposing lines. Both are good at the first pass out of the zone.

But to be a plus-21 given the players Haula faced?

“It is extraordinary,” Walz said.

It is about time, Haula said.

“I’ve been working on consistency and just blossoming as an NHL player,” he said. “That’s the biggest thing.”