PYEONGCHANG, SOUTH KOREA – The vibe around the U.S. men's hockey team in the moments after a stunning 3-2 overtime loss to Slovenia in Tuesday's Olympic opener did not feel like one of anger or panic. It felt oddly calm.

Members of Team USA certainly were frustrated over a lost opportunity with a last-minute flop, but their solid play for the first 40 minutes left them with mixed emotions, and they were not ready to beat themselves up too bad.

"I don't know if there's much we need to change," goaltender Ryan Zapolski said.

"Even after that I really like our team," forward Troy Terry said.

If nothing else, the Americans learned a valuable lesson. Two strong periods and a two-goal lead don't mean they can coast to the finish line.

"If you don't play for 60 minutes, you put yourself in a position where you might not win," coach Tony Granato said.

That's precisely what happened. A lack of energy and breakdowns defensively during a sluggish third period allowed Slovenia to seize momentum. Team USA looked helpless as everything unraveled.

"It's an unfortunate outcome and it's something we're going to have to get past," Terry said. "You saw how fast we are and we can make plays. Our issue right now is mostly defensively. We're all getting used to new systems and all that. But I have no doubt we're going to get better from here."

Granato will need the right touch and message to get his players rebooted for Thursday's second preliminary game against Slovakia.

"If you drag this one out and think about it for the next 36 hours, we're not going to be ready to play," he said. "This one is over and done with."

There are lessons to be learned from both sides. First, the good.

Team USA skated fast, forechecked aggressively and got rock-solid goaltending the first two periods.

Then everything fell apart.

Jan Mursak, the lone former NHL player on the Slovenia roster, tied the score with 97 seconds left in regulation and then scored the game-winner 38 seconds into overtime at Kwandong Hockey Centre.

Goals by Brian O'Neill and Wild prospect Jordan Greenway staked the Americans to a 2-0 lead. Granato couldn't have asked for much more, considering his players had practiced together as a group only five times before the opener.

"The first two periods we played pretty darn good hockey," Granato said. "The third period we got a little bit on our heels, probably let off the gas a little bit. They took advantage and kept coming."

Slovenia's Blaz Gregorc cut the lead in half on a shot from the point through a pile of bodies in front of the net. The Americans looked like they might survive in regulation, but Mursak scored on a rebound during a final flurry.

"I didn't see a shot on either of those first two goals," Zapolski said.

Team USA held the edge in shots 36-25, but Slovenia earned the win by dominating the final period.

"They came out hot [in the third period]," Greenway said. "They came out with more fire. We just didn't find a way to finish the game."

The response to that push was disappointing. The Americans had control of the game but for whatever reason, they lost their edge.

Moving forward they will need to shore up their defense after mistakes and confusion from a lack of continuity created too many scoring chances.

"I thought our energy in the third wasn't great," Granato said. "Could have been a little fatigued mentally. No excuses. We played as hard as we could. The first two periods were great hockey. In the third period they were the better team and it was good enough for them to get a win."