MELBOURNE - Australia's second-most populous state of Victoria reported no local novel coronavirus cases on Saturday for the second straight day, tapering down concerns about the Australian Open tennis tournament due to start in Melbourne on Monday.

More than 500 staff and players at the event, the year's first Grand Slam, tested negative for the novel coronavirus on Friday in re-testing required after a worker at their quarantine hotel caught the virus.

Positive cases could have spurred a lockdown or more limits on spectators attending the tournament.

Some 800,000 people attended the event last year but due to the pandemic authorities have approved 30,000 fans per day, about 50% capacity.

Qualifying matches were cancelled on Thursday while test results were pending.

The Victorian government has ruled that, except for players, masks will be mandatory for matches played under a closed roof. Following the most recent case, masks are required in all indoor spaces in Victoria.

"That applies to the stadia at the Australian Open when the roofs are closed, it's like any other indoor setting," Victorian Chief Health Officer Brett Sutton said at a press conference on Saturday.

Health Minister Greg Hunt said on Twitter that there was no new community coronavirus case across the whole of Australia Saturday.

"That makes zero on 16 of the last 18 days," Hunt wrote.

EXCITED TO PLAY

Australia has been far more successful than most advanced economies in managing the pandemic, with total infections at under 29,000 and 909 deaths so far.

This came thanks to strict and swift measures, high rates of community compliance and aggressive testing and tracing.

The country's borders have been closed since March of last year, meaning there will be almost no fans from abroad at the Australian Open.

More than 1,000 staff and players arriving from abroad were put into a two-week quarantine in Melbourne, leading to complaints from some frustrated players.

However, seven-times champion Serena Williams defended the mandatory quarantine procedures on Saturday.

"I think it was the best thing for all the players to do," the 23-times Grand Slam champion told reporters at Melbourne Park. "Even to have an opportunity to come and play was super exciting.

"I didn't have really any negatives. I realized that my life is one big quarantine because I don't really leave the house much. It wasn't much different than what I normally do."