Paris - US Open champion Emma Raducanu pulled out of this week's Mubadala World Tennis Championship in Abu Dhabi after testing positive for Covid-19, organisers announced on Monday.
The 19-year-old Briton was due to face Olympic champion Belinda Bencic on Thursday in the exhibition tournament.
Instead, Raducanu, who had already travelled to the United Arab Emirates, will now have to complete a period of isolation.
Providing she does not experience any lingering illness, however, the world number 19 should still be able to travel to Australia ahead of the first Grand Slam tournament of 2022.
"I was very much looking forward to playing in front of the fans here in Abu Dhabi, but unfortunately, after testing positive for Covid-19, I will have to postpone until the next opportunity," Raducanu said in a statement released by the organisers.
"I'm isolating as per rules and hopefully will be able to get back soon."
Raducanu, who became the first qualifier to win a Grand Slam when she beat Leylah Fernandez in the US Open final at Flushing Meadows, has been working with new coach Torben Beltz ahead of what will be her first full season on the WTA Tour.
The teenager will also be in isolation for Sunday's BBC Sports Personality of the Year show, where she is up against Tom Daley, Tyson Fury, Adam Peaty, Raheem Sterling and Sarah Storey in the public vote for Britain's top sportsperson of 2021.