The US Open will be without world No. 2 Simona Halep as she withdrew from the Grand Slam event amid fears for her health.
The 2019 Wimbledon champion, who recently won an exhibition tournament in Prague, withdrew from only the second Grand Slam of 2020 as she plans to stay in Europe during the Coronavirus pandemic.
"After weighing up all the factors involved and with the exceptional circumstances in which we are living, I have decided that I will not travel to New York to play the us open," she said on Twitter.
"I always said I would put my health at the heart of my decision and I therefore prefer to stay and train in Europe."
It now means that the US Open lacks star power as world No. 1 Ash Barty, 2019 US Open champion Bianca Andreescu, world No.5 Elina Svitolina, world No.7 Kiki Bertens and world No. 8 Belinda Bencic have all decided not to participate in the event.
Other players that have chosen to decline competing in the event also include defending champion Rafael Nadal, Gael Monfils, Nick Kyrgios and 2016 champion Stan Wawrinka.
The US Open begins on August 31.