The original plan, as laid out by Tennis Australia, the governing body of the Australian Open, was for everyone associated with the tournament to fly into Melbourne on carefully orchestrated chartered flights from Los Angeles, Miami, Abu Dhabi (where a WTA tournament had just concluded), and Dubai and Doha, both sites of the Australian Open qualifying tournaments.

Planes were just 20 percent full to allow for social distancing, and players, coaches and support staff members were tested for Covid-19 before takeoff. Players would quarantine for two weeks, though they were allowed out of their rooms for a total of five hours per day to practice, do physical training and eat at the tournament site.

The intent was to keep everyone safe, including Australians, who have endured strict lockdown mandates. With Covid-19 positivity near zero in the country, fans are permitted to attend the Australian Open, though in limited numbers. Tickets are available for one of three zones, each containing one of the show courts, but fans are required to stay within their specific zone for the duration of the session.

Andy Murray, a two-time Wimbledon champion, never got on the plane because he tested positive before leaving home, as did Madison Keys, the 2017 United States Open runner-up. Amanda Anisimova tested positive in Abu Dhabi and didn’t recover in time to travel to Melbourne. Roger Federer is still recovering from knee surgery that forced him to sit out most of 2020. All of those players have officially withdrawn from the tournament.

John Isner, the top-ranked American man, also withdrew, as did Rafael Nadal’s coach, Carlos Moya. Nicolas Massu, who coaches Dominic Thiem, tested positive right before his departure and will not attend the tournament.

While some players continued to practice throughout their quarantine, others had their tournament preparation upset when nine players on three flights tested positive for the virus upon arrival in Melbourne, including three nonplayers with the more contagious variant first found in Britain. That forced everyone on the three planes, including 72 players and hundreds of members of the support staff, into a complete lockdown for two weeks.