Rebecca Morrison had been due to skip Scotland only to test positive for coronavirus on the eve of the event, forcing her to miss the tournament opener at the CN Centre.

Alternate Fay Henderson also became infected by COVID-19, resulting in Scotland calling upon Beth Farmer.

But as Farmer, who works as a shepherd for her day job, is still travelling to Canada, Scotland had to field just three players against Switzerland, with Gina Aitken playing as skip.

Scotland opened the scoring with a single in the first end, but Switzerland then asserted their dominance on the match.

The Swiss team drew for two in the second end and then stole in the next four, including a steal of four in the fifth, on their way to a big win.

"It’s too bad for Scotland to have to go through this," Swiss skip Silvana Tirinzoni, looking to secure her third world title, said.

"I expect them to get stronger through the week, so maybe we were a little lucky to play them now."

According to Scottish Curling, Morrison is optimistic of joining her regular teammates Aitken, Sophie Sinclair and Sophie Jackson on the ice later in the competition while Farmer is set to compete in the early round-robin matches.

"The COVID challenge makes this harder on the team, but I know they are resilient determined athletes with a great coaching and support team around them," said Nigel Holl, executive performance director for British Curling.

"Adversity is a challenge that in sport you have to learn to deal with.

"I know this team will do that, will embrace Beth Farmer and represent Scotland with pride regardless."

Hosts Canada experienced a day of mixed fortunes as they opened their campaign with a 9-2 triumph against Italy only to then lose 6-4 to Norway.

Turkey came close to marking their debut with a victory as they lost 9-6 to Sweden before suffering an agonising 7-6 defeat to Japan.

The Czech Republic were drafted into the competition following exclusion of the Russian team over the invasion of Ukraine.

But they were on the end of a heavy defeat as the United States, skipped by Cory Christensen, powered to a 9-2 success.

"I was so impressed with how the girls played there,” said Christensen. 

"We came right out in the very first end and everyone was just spot-on.

"We all felt so comfortable on the ice we just decided to go for it."

In the other matches, South Korea edged Norway 7-6 and Denmark defeated Germany 11-8.

Competition is due to continue tomorrow with more round-robin action.