Jason Zucker, who spent the 2013-14 season traveling up and down Interstate 35 between the Twin Cities and Iowa, had to pay his dues in the American Hockey League before becoming a full-time NHLer. Same for teammate Marco Scandella, who refined his game for years before proving he was ready for a full-time spot with the Wild.

Some players, such as Cal Clutterbuck and Jared Spurgeon, took advantage of opportunities, arriving in the NHL because of injuries and, in the case of Clutterbuck, never leaving.

As it turns out, the AHL isn’t just a feeder system for players. It is for referees and linesmen, too.

This season especially, because of injuries to four referees and three linesmen, more up-and-coming officials have gotten a taste of the NHL by effectively being called up to the big leagues based on performance.

If you are a Wild fan, you might recognize the names of Jake Brenk, Evgeny Romasko, Dave Lewis and Chris Schlenker. They each have officiated Wild games this season, and they are four of nine referees who work primarily in the AHL but provide insurance to the NHL when the league’s short officials due to injury or illness. There are also four linesmen in that situation.

Brenk, 34, a Detroit Lakes, Minn., native and former Minnesota State Mankato forward, called Sunday’s game against St. Louis alongside veteran ref Chris Lee.

“Some won’t get NHL games depending on how they perform in the AHL, but when you have injuries, you have opportunity, so quite a few guys have been given opportunity to work in the NHL this year,” said Stephen Walkom, the NHL’s senior vice president and director of officiating.

Out for the season are three veteran linesmen — Derek Nansen (torn knee ligament), Jay Sharrers (hip injury) and Don Henderson, notoriously blindsided by Calgary defenseman Dennis Wideman in January, suffering a neck and back injury that very possibly ended his career. Linesman Steve Miller escaped serious injury in last week’s Wild-Toronto game, suffering a bruised quadriceps when he was nailed by a dump-in from the Maple Leafs’ Roman Polak.

Close to returning are four refs: Francis Charron; Dave Jackson; Chris Rooney, who ruptured his Achilles’ tendon before the season; and Steve Kozari, who had minor knee surgery.

“Because we have minor league guys that are performing great, we encouraged Steve to go get it done so he would be ready to go in the new year,” said Walkom, a former NHL referee. “Historically, we didn’t have a stable of great guys, so guys would work all year with that injury.

“Now, we’re not pushing guys to go back on the ice before they should. It’s nice to have that luxury.”

Training ground

Walkom is essentially the coach and GM of all NHL officials, and he runs them like a team. If an official goes down, he relies on Al Kimmel, in charge of scouting and development of officials, and AHL executive Mike Murray to tell him who is performing well enough to step into the NHL seamlessly.

“We try to operate the same way a real good team does,” Walkom said. “Real good teams, when someone goes down, they have someone ready.”

In the field, Walkom has officiating managers — a who’s who of former well-known referees: Paul Devorski, Don Koharski, Don Van Massenhoven, Bill McCreary, Mick McGeough and Rob Shick. Their job is akin to an assistant coach.

While Walkom always is coaching from afar, the officiating manager’s job is to “make sure attitudes are right, focus is right, to fine-tune guys all the time and to make them accountable,” Walkom said.

Even with injuries, the officials are run like a team. They have “team” doctors and a full-time medical trainer — Dave Smith, who used to work for the Florida Panthers and New York Rangers.

Once officials are cleared to work out, the Toronto-based Smith will travel to skate with them and simulate games.

“Then, they get cleared to our doctor, the same way the teams do it,” Walkom said.

Of the officials who split time between the NHL and AHL last season, six were promoted full-time to the NHL this season, including referees Garrett Rank, Kendrick Nicholson and Jon McIsaac.

“We wouldn’t put them in if we didn’t think they were good,” Walkom said. “We want guys to get careers. We don’t want to be firing guys. I put a lot of pressure on our scouting and development staff to make sure they give us top level talent.”

Young and old

All officials who split time between the NHL and AHL are employed by the NHL and are in the NHL Officials Association.

“I’ll put it this way: They all come to training camp,” Walkom said. “They’re on every one of our video sessions, they’re on every one of our e-mails, they get more coaching than anyone in the American Hockey League, so they’re very much in tune with the system we operate under and they understand the NHL standard and they get judged to it.

“I’m not going to say it’s perfect, but I must say I’m very pleased with their performance in almost all games. They all know they’re on a tryout every night. I just like the energy and work ethic I see from the guys, and I like how it rubs off on our team [of veterans]. Sometimes the energy and enthusiasm they bring to the game is contagious with the guys that have been there a while.”

Just like the players, officials are getting younger and younger. As an example, when the Wild recently played at Calgary, 29-year NHL linesman Shane Heyer, 52, was partnered with 30-year-old Trent Knorr.

Referee Mike Leggo, 51, is scheduled to retire this season after making his debut in 1998. As a means of giving back, like Greg Kimmerly last year, Leggo has been working some games in the AHL this season with the young call-up officials. Leggo then works with the same officials in the NHL.

“It says a lot about our guys,” Walkom said. “They are great mentors in the field, and I really believe they have a team culture and a real team mentality. And, it’s all for the purpose of serving the game. We have a great structure in place where no matter what happens in the NHL, we are prepared to serve the game with competent people.

“That’s basically our quiet goal.”