The WTA has created a tournament exclusively for the players unable to leave their rooms during quarantine for the Australian Open.

Victoria Azarenka, Bianca Andreescu, Angelique Kerber and Britain's Heather Watson are among those eligible.

The ATP events scheduled for the week before the Australian Open will be pushed back 24 hours.

Seventy-two players are currently confined to their rooms after positive cases on the chartered planes that brought them to Australia.

"This has been a particularly challenging time for the athletes in hard lockdown and we, along with the WTA and ATP, aim to do everything we can to help," said Australian Open tournament director Craig Tiley.

"These changes to the lead-in events have been made to give the 72 players a little bit of extra time to help them prepare. We also will prioritise them for things like practice sessions, gym and ice baths."

WTA chief executive Steve Simon added: "It will allow for our athletes coming out of the respected quarantine period to properly focus on their preparation in a return to competition."

Meanwhile, one case of Covid-19 among those in quarantine before the Australian Open - the first Grand Slam of the year - has been re-classified as negative.

There are now nine active cases among the 970 players and staff in two-week isolation in hotels in Melbourne. Spain's Paula Badosa is the only player to have publicly said she has tested positive.

Health officials in Victoria had previously revealed they were investigating positive cases for evidence of "viral shedding" - where those who have had the virus continue to shed non-infectious remnants.

On Saturday, officials said three of the nine positive cases - not players - were the more transmissible variant first discovered in the United Kingdom.

Portugal's Joao Sousa has withdrawn from the tournament despite testing negative, saying he will not travel to Melbourne "due to the strict rules of the Australian government".

Yastremska's provisional ban upheld

Dayana Yastremska's bid to have her provisional doping suspension lifted has been rejected by the International Tennis Federation (ITF).

The world number 29 was provisionally banned earlier in January for failing an out-of-competition doping test.

The Ukrainian denied using performance-enhancing drugs despite testing positive for mesterolone metabolite, an anabolic agent, in November.

Despite the ban, she had travelled to Melbourne for the Australian Open.

Yastremska, who has been ranked as high as 21 in the world, previously suggested the positive test was the result of a "contamination event".

The ITF's decision to dismiss Yastremska's application is subject to appeal to the Court of Arbitration for Sport.