LAUSANNE, Switzerland -- The Philadelphia Flyers were hoping to use their final preseason game against Lausanne in the 2019 NHL Global Series Challenge as a dress rehearsal for the regular season.

Instead, a 4-3 loss at Vaudoise Arena on Monday showed the Flyers just how much work remains before their opener against the Chicago Blackhawks in the 2019 NHL Global Series at O2 Arena in Prague, Czech Republic, on Friday (2 p.m. ET; NHLN, SN360, NBCSP, NBCSCH, NHL.TV).

"There's areas, and it's very evident, areas that we need to work on," Flyers coach Alain Vigneault said. "As I've said many times, we've got a lot of work to do, and we're going to do it."

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Sean Couturier had a goal and an assist for Philadelphia, which went 1-3-3 in the preseason. Carter Hart allowed four goals on 10 shots and was replaced 3:02 into the second period by Brian Elliott, who made 14 saves.

Video: PHI@LAU: Couturier pots goal from side of the net

Lausanne took a 3-0 lead in the first period on goals by Yannick Herren at 4:08, Cory Emmerton at 10:29, and Joel Genazzi at 13:26.

Joel Vermin one-timed a shot past Hart on the power play at 3:02 of the second period to extend the lead to 4-0.

"I think the first few shifts were pretty good, we got a few chances," Couturier said. "Then they capitalized, and our PK was bad tonight (0-for-2), probably cost us the game. I thought as the game went on we controlled most of the play. But at the same time, when you're down three or four goals, it's tough against any team to come back."

Philadelphia started to push back when Claude Giroux tipped a Couturier pass past Lausanne goalie Tobias Stephan at 5:37 of the second period to make it 4-1.

Video: PHI@LAU: Giroux nets juicy rebound in front

Giroux had another chance to trim the lead when he was awarded a penalty shot at 3:49 of the third, but he was stopped by Luca Boltshauser, who replaced Stephan with 7:45 remaining in the second period, after losing control of the puck.

Rookie forward Connor Bunnaman got a loose puck in the crease and scored on a backhand past Boltshauser at 15:23 of the third to make it 4-2.

With 2:10 remaining, rookie forward Carsen Twarynski battled for a puck in front and knocked it under Boltshauser to Couturier, who scored at the right post to cut it to 4-3.

"Right now, we have a few younger players that are playing extremely hard and very competitive," Vigneault said. "I need to find out a little bit more of some of our older guys, what they can do, what they can bring to the table. And we will."

The Flyers continued to push for the tying goal, but Boltshauser and Lausanne were able to hold off the late rally.

"I think as the game went on, we started playing a little bit more our game and have a little bit more confidence," Giroux said. "You want to go into the season with a high and that wasn't the case tonight."

Vigneault fiddled with his forward lines throughout the game, including four new combinations to start the third period.

"There's no doubt that I have not yet found combinations that I'm comfortable with both defensively and offensively," Vigneault said. "I've said this many times throughout camp that we have a lot of work to do. And we do. We're in the process right now, we're trying to focus on certain areas that we need to improve. And that's what we're going to try and do."

Despite a disappointing result, forward Jakub Voracek kept things in perspective with the regular season less than a week away.

"You start the season 3-0 nobody's going to remember," he said. "Lot of time it's happened where we had a good preseason and a bad start. So hopefully we turn it around and we're going to play better and have better results in the regular season."

Video: PHI@LAU: Vermin hammers home power-play goal

Philadelphia will spend one more day in Lausanne before departing for Prague, and although the result Monday wasn't what it wanted, the players still found their time in the city a good experience.

That included a boisterous, sold-out crowd of 9,600 chanting and celebrating at every opportunity. The standing-room section behind the Lausanne net made as much noise as the crowds the Flyers are used to playing in front of at Wells Fargo Center, which has a capacity of 19,500.

"The fans, the crowd, it's different than back home," Couturier said. "That standing section is pretty cool. They're loud there, they support their team, they love hockey. They're passionate fans.

"The whole experience, obviously we wish we had a better result, but it was different. It was nice."