"I am following protocol and isolating. I will miss Lienz. Good luck to all my teammates...I'll cheer for you. We are grateful for all your support. She tweeted Monday, "I'll see you in 2015!"

Shiffrin won gold at the Sochi Olympics in the slalom and the Pyeongchang Olympics in the giant slalom. He is expected to be a strong contender at this year's Beijing Olympics. They are scheduled for February 4. China is doubling its efforts to combat new viruses, so the participation of the skiing star is in doubt.

Shiffrin is the latest elite skiing athlete to be positive for COVID-19. Lara Gut-Behrami (former overall champion), Katharina Liensberger, Austrian world champion and Alice Robinson from New Zealand all tested positive for the virus.

Lienz will host Wednesday's women's giant and slalom races. Shiffrin is currently the women's overall leader. However, she may not be able to retain her overall World Cup title in time if she doesn’t recover. With only a few more months to go in the season, Sofia Goggia from Italy trails Shiffrin by just 115 points. Shiffrin took home her sixth gold medal and a ninth career world medal last year -- one more than Lindsey Vonn, who is at the top of all-time American medalists.