A dispute over virus testing suggests a lingering mistrust of Russia.

The concern showed up most obviously in the masks, the ones suddenly worn on the benches, by the referees and, remarkably, by the women playing Olympic hockey in Beijing on Monday.

The Games, long cloaked in rhetoric about sportsmanship, shared values and unity, veered into an open exhibition of suspicion when misgivings over coronavirus testing for the Russian women’s hockey team led to a 65-minute delay of a meeting against Canada. When the game finally began, it did so under a health precaution rarely seen during elite competition: Everyone was wearing a mask.

The episode, which the International Ice Hockey Federation formally attributed to “safety and security concerns,” was also a glimpse into the Western skepticism of a Russian Olympic apparatus that has a long record of bending or breaking rules, particularly around doping.

Although Canadian officials avoided accusing their Russian counterparts of misconduct, they had reason for concern. The Russian squad spent part of last week in quarantine after a series of positive tests within the team.

“We wanted to make sure that everyone that was participating was healthy and making sure we’re lowering the risk, so we just decided to wear a mask,” Rebecca Johnston, a Canadian forward, said of her team’s decision to play in masks under their face shields. Asked whether the Canadians had feared active cases on the Russian team, she replied: “I think we weren’t sure what was going on.”

Sports leagues around the world insist that viral transmission is unlikely during competitions, and cases directly linked to games are believed to be rare. Still, with stringent health protocols in effect at the Games, where the Chinese authorities have imposed a so-called bubble to separate Olympic participants from the broader population, the Canadians seemingly saw little reason to take a risk, especially for a team that is expected to contend for the gold medal.

There were indications that the Russian team remained affected by the virus. Players were missing from its bench, and Alexandra Vafina, a forward, suggested that the team was still subject to the Olympic protocols for close contacts, which include testing twice a day.

The team, Vafina said, was “trying to follow all those strict rules and prevent any spread of disease.” Another player, Anna Shibanova, suggested that laboratory delays might have contributed to the timing of the team’s latest results, which arrived during the game.

Yevgeni Bobariko, the Russian coach, said he had been told that the Canadian team had requested that both teams wear masks. He added that he did not sense a “shadow of mistrust.”

Both teams wore masks until the start of the third period, when the Russians returned to the ice without face coverings. Natalie Spooner, a Canadian player, said she had been told that the Russian team’s test results had come back as negative by then. Canada led, 4-1, at the time and elected to remain masked.

“It was as simple as, ‘We wore it for 40, let’s wear it for the extra 20,” said Troy Ryan, Canada’s coach. “If health and safety is a concern, it doesn’t just switch.”

A Russian television station accused the international federation, which administers the Olympic tournament, of “unilaterally” altering testing procedures before Monday’s game.

In response to a request for comment about that assertion, a spokesman said the federation “did not change any of the testing protocols during the tournament.” In a separate statement, the federation said the game had been delayed “with a view to ensure full understanding of the teams about the health and safety measures in place.”

Canadian players said they had sometimes practiced in masks.

“It’s a little bit harder to see the puck if it gets in the way,” Spooner said. “But I would say the biggest difference is just talking. You’ve got to talk so much louder for everyone to hear you on the ice.”