World number one Ashleigh Barty has ended her season and will not defend her WTA Finals title next month because of the quarantine rules she would face on her return to Australia.
The Finals were last held in 2019, but Barty will not travel to Guadalajara, Mexico for this year's event.
The Australian, 25, said she did not want to "compromise" her preparation for January's Australian Open.
"It was a difficult decision," the Wimbledon champion said in a statement.
"But I need to prioritise my body and my recovery from our 2021 season and focus on having the strongest preseason for the Australian summer.