Andy Murray has reportedly tested positive for coronavirus, putting his participation in next month’s Australian Open in doubt.

Murray had been planning to fly to Melbourne this week to begin a two-week quarantine required by the tournament, which begins Feb. 8, three weeks later than usual because of the pandemic.

Under rules agreed to by the tournament and Australia’s government, players, coaches and anyone else traveling to the event must return a negative virus test before departing. More testing — and strict rules about movement, housing and playing — await upon arrival.

Murray, who was reported to be not showing any symptoms of Covid-19, was said to be hopeful he might still be able to play in the tournament.

A three-time Grand Slam single champion, Murray, 33, has fallen to No. 123 in the world rankings after playing only a handful of matches in 2020 because of a pelvic injury. He received a wild card to this year’s Australian Open, where he is a five-time runner-up.

The tournament has put in place strict rules to try to limit the spread of the virus as hundreds of players and their entourages, as well as news media members and other support staff, arrive in the country from around the world. Bubbles will be set up for everything from housing to training, and players and others will be subject to daily virus testing.

During the 14-day quarantine period after they arrive in Australia, players will be able to leave their hotel rooms to work out for no more than five hours a day at a secure facility. The Victoria government said hundreds of staff members had been hired to attend to the needs of those in the quarantine hotels, and that the police would play a role in enforcing quarantine rules.

Qualifying for the Australian Open has been taking place in Qatar and the United Arab Emirates.

Some players have simply stayed home. The American John Isner, ranked No. 25, said he would not play in the event because the quarantine measures would keep him away from his family for too long.

No. 5 Roger Federer will also miss the event, citing knee problems. Most of the other top-ranked men’s players are still planning to attend.

The American Tennys Sandgren, ranked No. 50, flew to Australia despite a recent positive test. He received special clearance after health officials determined that he was not infectious, because he showed no symptoms and had previously tested positive for the virus in November. “Some people who have recovered from Covid-19 and who are noninfectious can continue to shed the virus for several months,” the tournament said.

After a spike in August, Australia has largely contained the virus through strict border closings lockdowns and other measures. The country is currently averaging about 20 new cases a day.