Slater Koekkoek and Carl Dahlstrom are main — but not only — competitors for Blackhawks’ 7th defenseman role

Slater Koekkoek spent his summer weekends in the most low-key way imaginable: living out of a trailer by the Rideau River outside Ottawa, muskie fishing every morning and evening.

Then he arrived in Chicago and found himself immediately thrust into the most heated battle imaginable for a seventh-defenseman role.

The Blackhawks treated their defense this offseason like an airline treats an in-demand flight: They overbooked it. Entering training camp, they own eight blue-liners on one-way contracts, plus veteran addition Philip Holm and top prospect Adam Boqvist. Only seven will make the Opening Day roster, and only six will play in that first game.

In other words, some players will be squeezed out — and they won’t be rebooked on a later flight.

“That’s the nature of the game; everybody’s competing for a job,” Koekkoek said.

Koekkoek, 25, and Carl Dahlstrom, 24, are the true bubble guys. The former, a onetime top prospect acquired from the Lightning last season, had five points in 22 appearances with the Hawks. The latter, the Hawks’ 2013 second-rounder, had six points in 38 games last season.

If Dahlstrom makes the team, it’ll functionally be his second year in Chicago — he made only 11 appearances in 2017-18 — after two years in Rockford and two years with the Swedish club Linkopings HC.

At each stop, he felt far more comfortable in the second year, and it showed in his performance. That trend was especially noticeable with the IceHogs. His production from the blue line jumped from 11 to 28 points in the second year (which also happened to be Jeremy Colliton’s year in charge).

“Throughout my career, my first year has always been a transition year — there’s new ways of playing at every team everywhere you go,” Dahlstrom said. “My first year, I was decent. My second year, I was a lot of better. . . . I’m hoping to do the same thing here, continue on the same path.”

Koekkoek is beginning, rather unbelievably, his sixth professional season, although a combination of injury issues and stalled development with Tampa Bay means he has never played more than 35 NHL games in a season.

Holm, meanwhile, is the dark-horse candidate, the late-summer signing who excelled in the AHL in 2017-18 and in Russia’s Kontinental Hockey League in 2018-19.

With a solid mixture of size (6-1), poise and puck-moving ability, the 27-year-old journeyman has impressed in camp. He had a goal and an assist in 21:58 in his preseason debut Tuesday.

“I’m more of a two-way player,” Holm said. “As a defenseman, our main job [is] to try to play solid on the defensive end. But in today’s hockey, it’s a lot about skating and, especially for [defensemen], to join the rush. So I want to try to contribute in the offensive game, too.”

Boqvist should get some looks with the Hawks later this season because the dynamic youngster certainly has a higher long-term ceiling than Koekkoek, Dahlstrom or Holm, but he’ll likely begin in the AHL, adjusting to the defensive requirements of the pro game.

That seventh spot will scarcely receive a moment’s glance in many organizations, but given the Hawks’ back-end struggles of a year ago, the winner determined in the next few weeks will have practically won the Hunger Games.

They just don’t like thinking of it that way.

“I can’t really focus on the other guys,” Dahlstrom said, echoing Koekkoek and Holm. “I’m just trying to be the best version of me and see where that takes me.”