Alex de Minaur is "shattered" to be missing the Tokyo Olympics after he tested positive for COVID-19.
De Minaur was the headline name of Australia's Olympics men's tennis team, alongside Nick Kyrgios.
However, Kyrgios pulled out last week due to a concern over the decision to ban fans from attending events due to a spike in coronavirus cases in Japan.
Now world number 17 De Minaur has joined a list of absentees which already includes Roger Federer and Rafael Nadal, while the woman's tournament will be without Serena Williams and former medallists Victoria Azarenka and Angelique Kerber, who withdrew on Friday.
"We have been advised that Alex de Minaur has had a positive test, as a consequence, Alex, sadly will be unable to join the Australian team," Australia's chef de mission Ian Chesterman said.
"We are very disappointed for Alex and he is shattered at not being able to come. It has been his dream to represent Australia at the Olympic Games since he was a child, but he sent his best wishes for the team."
De Minaur undertook both the mandatory 96-hour and 72-hour PCR tests before departure. However, Australia are confident his positive result will have no impact on the rest of their team.
The 22-year-old was set to take part in his first Games, representing Australia in the singles and doubles.
"No other tennis players have had physical contact with Alex since he left Wimbledon on 5 July, where he tested negative," Chesterman added.
"All other Australian players have tested negative since. We look forward to welcoming those athletes into our team.
"We need to protect this bubble and Alex has been caught up in that system. While we will miss Alex, he understands the reasons why he cannot be with us."