Briton Cameron Norrie's hopes of qualifying for November's ATP Finals took a hit after he was forced to pull out of this week's Japan Open due to a positive COVID-19 test.
Norrie also withdrew from the Korea Open on Friday, ahead of his quarter-final tie against American Jenson Brooksby.
"Unfortunately I had a positive COVID test in Korea and wasn't able to compete in the rest of my matches. I have no symptoms and I am feeling 100%," Norrie wrote in a post on Instagram on Sunday.
"I was really hoping to go to Tokyo but because of the quarantine period I will not be able to play there."
The season-ending ATP Finals on the men's tour is played between the top eight singles players and doubles teams and will be held from Nov. 13 to 20.
Norrie, now ranked eighth, said last month he would be playing at the Stockholm Open, the Erste Bank Open and the Paris Masters ahead of the ATP Finals.