STOCKHOLM -- The NHL will return to Europe next season, playing regular-season games in the Czech Republic and Finland in the 2020 NHL Global Series and preseason games in Germany and Switzerland in the 2020 NHL Global Series Challenge.

The Boston Bruins and Nashville Predators will open their 2020-21 seasons at O2 Arena in Prague in October. Later in the fall, the Colorado Avalanche and Columbus Blue Jackets will play two regular-season games at Hartwall Arena in Helsinki.

The Bruins and Predators will finish their respective training camps in Europe, with the Bruins playing a preseason game against Adler Mannheim at SAP Arena in Mannheim, Germany, and the Predators playing SC Bern at PostFinance Arena in Bern, Switzerland.

Dates and ticket information will be announced later.

"There is a simple reason we believe that every single game that we play in Europe sells out in a matter of hours," NHL Commissioner Gary Bettman said while making the announcement before the Buffalo Sabres and Tampa Bay Lightning played in the 2019 NHL Global Series at Ericsson Globe on Friday. "And it's the same reason that the European game of the week with our media partners has been so successful.

"Hockey is truly a global game, and hockey fans in Europe obviously love the game, and we love the fact that they love the game, which is why we keep coming back. No matter where fans are watching, there is a worldwide recognition of the incredible speed and skill and talent that's on display in today's NHL."

The NHL will have played 28 regular-season games in Europe after the Sabres and Lightning complete a back-to-back set in Stockholm on Saturday (1 p.m. ET; NHLN, SN1, SUN, MSG-B, NHL.TV).

The 2020 NHL Global Series will represent the fourth straight season and ninth in all that the NHL has played regular-season games in Europe. It will feature the sixth regular-season game at O2 Arena and the seventh and eighth games at Hartwall Arena.

Commissioner Bettman said he was pretty certain the NHL would return to Sweden in two years, in Stockholm or a couple of other cities that have expressed interest, and the NHL is discussing internally playing in Eastern European countries, including Russia.

"My own belief is, if we're going to play games in Russia -- and we know there's great interest in our game there -- it would most likely be from our standpoint regular-season games with two NHL teams," Commissioner Bettman said.

Commissioner Bettman said the demand for NHL games overseas has grown by "an order of magnitude."

"There's always been a demand, at least throughout my 27 years at the NHL, for hosting games outside of North America," Commissioner Bettman said. "But the demand is pretty intense right now, just like the demand is in North America for All-Star Games, drafts and outdoor games."

Asked about hosting an outdoor game in Europe, Commissioner Bettman said the crowd was polled on the idea during a seminar with the Swedish Ice Hockey Federation on Friday.

"Not one hand went up, because the view was, if we're going to bring the NHL experience here, let's bring the NHL experience here," Commissioner Bettman said. "The outdoor games are less typical, more big tentpole events, and we do those in North America because that's where it makes the most sense. But we're not getting that there's a real demand to do an outdoor game in Europe. That may change over time."

More than 30 percent of NHL players come from outside North America.

The Bruins have two players born in the Czech Republic: forwards David Krejci and David Pastrnak.

"I was very excited to learn that the Boston Bruins would be heading back to my home country to play in the 2020 NHL Global Series in Prague," said Pastrnak, who is from Havirov, Czech Republic. "I remember driving to O2 Arena as a kid to go see the Bruins play the Coyotes back in 2010 for the NHL Premiere games. The passionate fans and atmosphere were something I'll never forget. I can't wait to feel that energy again from the ice in Prague and Mannheim."

The Predators have two players who were born in Switzerland: defenseman Roman Josi, who was born in Bern, and Yannick Weber.

"It means a lot for our entire organization to get the opportunity to play games in the Czech Republic and Switzerland," Josi said. "We are proud of what our franchise has accomplished over the past couple seasons and now are lucky enough to play in not only the (2020 Bridgestone NHL) Winter Classic, but in the Global Series too. We are all honored that we get the chance to play in Europe and everyone on the team is excited for the opportunity.

"Before coming to North America, Bern was the only team I had ever played for growing up and I watched them play when I was little. I grew up five minutes away from their rink and it's my hometown club. It's going to be so special for me and I can't wait for the game."

The Avalanche have two players born in Finland: forwards Joonas Donskoi and Mikko Rantanen. The Blue Jackets have two born in Finland: goalie Joonas Korpisalo and defenseman Markus Nutivaara, plus general manager Jarmo Kekalainen.

"The Columbus Blue Jackets are proud and excited to be participating in next year's NHL Global Series in our 20th season as a member of the National Hockey League," said Kekalainen, a native of Kuopio, Finland. "It means a great deal to me personally, knowing how passionate Finnish hockey fans are, to be a part of bringing our team to the place where my NHL dreams began as a young hockey player."

For the updated ticket details and to gain access to special ticket pre-sale offers, fans should register at NHL.com/GSSwitzerland and NHL.com/GSCzechRepublic.

"I think hockey worldwide is in a good place," Commissioner Bettman said. "It starts with the fact that the game as it's played has never been faster and more entertaining, more exciting. The players have never been more skillful. The game has never been younger. And the game at the NHL level has never been more competitive. And I think that in the global NHL world, the global hockey world, the vital signs are all good."