The war in Ukraine threw a wrinkle into the National Hockey League’s planned return to Europe next month to play its first games outside North America since the start of the pandemic.

The Czech Foreign Ministry told two NHL teams opening their seasons in Prague that any Russian players would not be welcome because of Russia’s invasion of Ukraine.

It may not amount to an outright ban and league officials downplayed the potential impact, but it added a layer of uncertainty to a Global Series the NHL is proud of.

The Nashville Predators and San Jose Sharks are set to play regular-season games Oct. 7 and 8 at Prague´s O2 Arena as part of the series that is intended to put the world’s top players on display, primarily in Europe.

There are not many Russians on the two rosters: Nashville has forward Yakov Trenin and San Jose has Alexander Barabanov, along with Evgeny Svechnikov, who is in training camp on a tryout agreement.

“We can confirm that the Czech Foreign Ministry has sent a letter to the NHL to point out that, at this moment, the Czech Republic or any other state in the (visa-free) Schengen zone should not issue visas to the Russian players to enter our territory,” Deputy Foreign Minister Martin Smolek said in a statement.

NHL Deputy Commissioner Bill Daly told The Associated Press on Thursday he has “no concern” with players either traveling to Prague or suiting up to take the ice. He added that players have appropriate visas.

The NHL never considered banning Russians, many of whom are some of the most skilled hockey players in the world. Commissioner Gary Bettman told The AP during the spring Russians “are performing in the NHL for their NHL team for NHL fans.”

The NHL is returning to Europe for its first games outside of North America since 2019. After the two games in Prague, the Avalanche and Columbus Blue Jackets will play twice in Tampere, Finland, on Nov. 4-5. The Finnish government’s position on Russian players was not immediately clear.

Czech NHL great Dominik Hasek has led the opposition to Russian players coming to Prague since the games were announced in April. Hasek approached the upper house of Parliament, the Senate, the government and the Foreign Ministry about the issue.

“It’s very important for the support of our Ukrainian ally and safety of our citizens,” Hasek said in an interview for a Russian broadcaster. After it was not aired in Russia, he published it in Czech media.

“Yes, we don’t want any promotion of the Russian aggression here,” Hasek posted on Twitter after the ministry´s move. “We´re guarding our lives and the lives of our allies in the first place.”