The mood was upbeat and lively as the Missouri Mavericks entered the Independence Events Center locker room prior to a Monday afternoon practice session.

They were home – and that’s the place coach Scott Hillman and his top-seeded team wanted to be if their first-round playoff series came down to a must-win Game 6 against the Arizona Sundogs.

“We played 66 games during the regular season to get to this point,” said Hillman, whose Mavericks face a win-or-go-home 7:05 contest tonight against Arizona, a surprising No. 8 seed that owns a 3-2 advantage in the best-of-seven series. “We have to win tomorrow night, and we have the opportunity to do it on our own ice because we worked so hard during the regular season. The past two years, we have lost a must-win game on the road; tomorrow, we get the opportunity to play at home in front of the best fans in the league.”

Missouri and Arizona split two games last week at the Events Center, then the host Sundogs won two of three at Tim’s Toyota Center in Prescott Valley, Ariz., including a 4-3, two-overtime, 90-minute marathon Saturday night.

“There is a real sense of urgency, along with a sense of confidence in that locker room,” said Hillman, moments before a closed-door meeting. “We came within 29 seconds of winning that game in Arizona, and we lost because of some terrible mistakes. We can’t – and we won’t – make those mistakes Tuesday night.”

The Mavericks played Saturday night without team captain Sebastien Thinel, who was suspended by the league for one game (for making contact with an opponent’s head with his stick in the third period of Friday night’s 3-1 Mavs win), forward John-Scott Dickson (upper body injury) and Tyler Currier (upper body injury).

Because the Mavericks were short-handed, they signed amateur Pete Massar – a former college roommate of rookie defenseman Anders Franzon – who scored two goals in his first pro game.

“The players weren’t that excited about Pete because they did not know what type of player he is,” Hillman said, “but I was excited because we had scouted him and knew that he could make an impact. No one could foresee two goals.

“He made quite an impact and he will be in there Tuesday. We just don’t know about Dix (Dickson) and Currier. They are questionable, and we could certainly use them out on the ice. But whether they play or not, we are confident with the players we have ready to go.”

It’s not only Hillman who is taking an optimistic approach to tonight’s game. So are his players.

“I don’t see anyone pushing a panic button,” said forward Andrew Courtney, who had a goal in each playoff game until Saturday night. “We’ve been in this position before, and we know what we have to do to win.

“We’re home, and we need to win Tuesday night. After we win Tuesday, we think about Wednesday. Until then, it’s a practice at a time, a period at a time, a game at a time, and we are excited to get back out on the ice.”

So is veteran forward Colt King, whose Rapid City Rush team won the CHL championship in 2009-2010 – the Mavericks’ first season in the league.

“At the end of the day Saturday, we were all disappointed in the outcome, but not in the way we played,” King said. “They got a couple of good bounces. Give them credit – they tied it up late and won it in the second overtime. But we have a lot of confidence going into Tuesday’s game.

“We’re home, we have the best fans in the CHL, we’re sleeping in our own beds and eating home cooking. We’re going to be ready to play. Believe me, we’re going to be ready.”

Arizona’s Mike Forney scored two goals in the second period Saturday night sandwiched around a goal by Missouri’s Eric Castonguay to make it 2-1 going into the third period.

Massar scored his first two pro goals at the 7:23 and 13:37 marks, and it appeared the Mavericks might take a 3-2 lead in the series until Justin Pender scored a sixth-attacker goal with just 29 seconds left in regulation.

Following a scoreless first overtime, the Sundogs won the game on Johan Ryd’s even-strength goal at the 10:32 mark of the second overtime. The 90-minute, 32-second game marked the longest in team history for both the Sundogs and Mavericks.

“I felt stronger and stronger as the game went on,” said goaltender Shane Owen, who faced 56 shots and stopped 52. “My adrenaline was really pumping.”

Arizona outshot the Mavericks 18-9 in the two overtimes – including 8-2 in the second OT – and 56-48 overall.