Bianca Andreescu has confirmed that she won't be defending her US Open title.
Last year's women's champion at Flushing Meadows says she does not have enough time to properly prepare for the tournament.
The Canadian hasn't competed since suffering a knee injury in October.
Andreescu just the latest high-profile member of the WTA Tour to make themselves unavailable.
This year's US Open is scheduled to get underway behind closed doors in New York on August 31.
However, world no.1 Ashleigh Barty, no.5 Elina Svitolina, and no.7 Kiki Bertens will all be absent. They've all blamed uncertainty surrounding COVID-19 as their reasons.
— Bianca (@Bandreescu_) August 13, 2020
Andreescu won her first Grand Slam at Flushing Meadows last year, completing a 6-3, 7-5 victory over Serena Williams.
But the world no.8 says unforeseen circumstances "have compromised my ability to prepare and compete to the degree necessary to play at my highest level."
The men's draw hasn't escaped big-name withdrawals either.
Defending champion Rafa Nadal said last week, "The [COVID-19] situation is very complicated worldwide, the COVID-19 cases are increasing, it looks like we still don’t have control of it."
However, Novak Djokovic will be at Flushing Meadows. The world no.1 said on Thursday, "The prospect of competing again makes me really excited."
Bianca Andreescu statement:
After many discussions with those closest to me, I have made the difficult decision not to return to New York this year.
I have taken this step in order to focus on my match fitness and ensure that I return ready to play at my highest level.
The US Open victory last year has been the high point of my career thus far and I will miss not being there.
However, I realize (sic) that the unforeseen challenges, including the Covid pandemic, have compromised my ability to prepare and compete to the degree necessary to play at my highest level.
I want to express my appreciation to the USTA and the WTA for all of their efforts in making the event happen.
I look forward to joining my competitors back on court soon.
Download the brand new OffTheBall App in the Play Store & App Store right now! We've got you covered!
Subscribe to OffTheBall's YouTube channel for more videos, like us on Facebook or follow us on Twitter for the latest sporting news and content.