The echoes at Mariucci Arena are different this week. Mike Guentzel's whistle blows at a different rhythm and his voice more loudly than the usual tones heard throughout a Gophers hockey practice.

It's Guentzel's team this week.

The associate head coach is the acting head coach while Don Lucia leads the USA National Junior Team at the International Ice Hockey Federation World Junior Championships in Malmo, Sweden.

"Guentzel is running the show now. Everyone has a lot of respect for him," Gophers defenseman Mike Reilly said.

As for the different mood: "His moods change a little bit every once in a while. When we're doing well in a game he's upbeat, but if we're down and need someone to help pick us up, he's definitely there to get on us about it. … He's honest and that's what we need."

Guentzel, who mostly works with the Gophers defensemen, assumed role as acting head coach after the team's trip to Michigan State. He and assistant coach Grant Potulny ran practices for two days before a 16-day winter break and took over again after Christmas.

The long break didn't give Guentzel much time to make major changes to the Gophers' system. There wasn't much need for change, either. The Gophers (11-2-2 overall, 2-0-1 Big Ten) return to competition ranked No. 1 in the USCHO and USA Today/USA Hockey Magazine polls.

Everything feels similar to if Lucia were around, Reilly said.

"The way we run things around here, Grant and I get very involved with special teams, with practice planning, with running practice warm-ups and running drills in practice. … I don't think much has changed," Guentzel said. "Just try to keep it on the tracks this week. Hopefully we can keep playing. We're trying to implement some new guys in new spots. Obviously Brady [Skjei] and Hudson [Fasching] being gone creates some new opportunities for other guys. … Hopefully we can develop some young guys' confidence coming out of the break. "

Sophomore defenseman Skjei and freshman forward Fasching are competing with the USA National Junior Team in Sweden.

Gophers senior defenseman Jake Parenteau is recovering from surgery on a broken leg is expected to miss at least another month. Banged up freshman forward Vinni Lettieri is expected to play, while senior forward Tom Serratore will be a game-time decision.

The Gophers will play with five defensemen, Guentzel said. Reilly is confident the remaining group will operate fine. They've experienced playing with five defensemen on multiple occasions this season when a teammate went down early in the game.

• The Gophers remained in good shape over the long Christmas break. Senior captain Nate Condon said most of the team was around campus skating and working out.

• Don Lucia and the USA National Junior Team finished the preliminary round 3-1 and in second place behind Canada. They advance to face Russia in Thursday's quarterfinals.

• This weekend's Mariucci Classic features the No. 1 and No. 2 teams in college hockey. Wins by the No. 1 Gophers and No. 2 Ferris State on Friday would set up a battle of top teams in Saturday's championship game.

• Readers and fans share your opinion in honor of Mariucci Arena's 20th anniversary. Do you have a favorite Mariucci Arena hockey moment? Also, who are the best players (even opponents) to skate at Mariucci? Let me know your thoughts by Wednesday night with an email to jason.gonzalez@startribune.com. Your help will factor into Friday's results.

Gophers associate head coach/acting head coach Mike Guentzel: