Alexei Popyrin is the latest Australian tennis star to pull out of the US Open due to concerns about coronavirus.
Popyrin made a run to the third round of this year's Australian Open after a breakout 2019, during which he cracked the top 100 for the first time.
The 20-year-old world number 103 joins Nick Kyrgios and women's world number one Ash Barty in withdrawing from the major, which is set to start on September 1.
The event will also be without men's world number two Rafael Nadal, due to coronavirus concerns, and fourth-ranked Swiss great Roger Federer, due to injury, while Federer's countryman and 2016 champion Stan Warinka has also opted out because of "the health situation in New York".
The women's draw has also been hit hard, with two more players from the top 10 joining Barty on the sidelines over the weekend.
World number five Elina Svitolina — who made the semi-finals of the Australian Open, Wimbledon and US Open last year — and seventh-ranked Dutchwoman Kiki Bertens are also gone.
Popyrin's withdrawal means 2012 US champion Andy Murray, who had been granted a wild card at the tournament, will now move into the main draw.
The French Open, traditionally the second major of the year, starts on September 27, meaning anyone who wanted to play both would only have a two-week turnaround from hard court to clay if they reached the final.
This year's Wimbledon was cancelled.
