British No 1 Cameron Norrie has been forced to pull out of the Korea Open after testing positive for Covid-19.
Norrie was due to play a quarter-final match against American Jenson Brooksby on Friday after beating Japan's Kaichi Uchida in the previous round, but the 27-year-old tweeted on Sunday saying he had tested positive for Covid-19.
"Unfortunately I had a positive test in Korea and wasn't able to compete in the rest of my matches," Norrie said on social media. "I have no symptoms and I am feeling 100 per cent. It's been a complicated situation and I appreciate the Republic of Korea trying their best to be amicable in a very tough situation.
"I was really hoping to go to Tokyo but because of the quarantine period I will not be able to play there. Looking forward to getting back to Europe for the indoors."
Norrie, who is currently world No 8, must maintain a top-eight ranking to qualify for the season-ending ATP finals in Turin in November.
He has won two titles this year, reached the semi-finals of Wimbledon and made the top 10 for the first time in his career.
Norrie is the third seeded player to withdraw from the Korea Open after sixth seed Borna Coric dropped out on Monday and third seed Taylor Fritz withdrew on Thursday.
The final of the Korea Open in Seoul will pit fourth seed Denis Shapovalov against Japan's Yoshihito Nishioka.