Last year, the star athlete won her seventh Australian Open - while eight weeks pregnant, thank you very much. She later gave birth to daughter Olympia in September, and then Wednesday Alexis Ohanian and in November.
But her form isn't ready for Grand Slam action, she said.
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This would also jeopardise finance minister's target of bringing down the fiscal deficit to 3% of GDP by 2018-19. However, there is a difference between the way manufacturing data is calculated in the GDP and the IIP.
After 11 months off, Williams was defeated 10-5 in a supertiebreaker after she split the first two sets with French Open champion Jelena Ostapenko in an exhibition match at the Mubadala World Tennis Championship. Despite this, she made it clear afterwards that she missed being on court and was desperate to play at Melbourne Park, where she has been crowned champion seven times.
The professional athlete was scheduled to defend her title later this month.
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A mini-heatwave will see temperatures soar to 45C in parts of the city, sending Sydneysiders scurrying to escape the sun. CEO of Surf Life Saving NSW, Steve Peace, warned members of the public to be extremely careful on the state's beaches.
Australian Open tournament director Craig Tiley said Williams waited as long as she could before letting organizers know she wouldn't be able to compete.
Williams, whose Grand Slam tally is just one shy of the all-time record held by Australian Margaret Court, said she was disappointed to withdraw, but looked forward to returning in the future.
Few players have successfully bounced back after giving birth, and even fewer have managed to go on to win Grand Slam titles. Commencing from January 15, many big names will be missing from the Australian Open this year due to health issues. Murray has returned home after failing to recover from a hip injury sustained a year ago, while Nishikori has been on the sidelines since August due to a torn tendon in his right wrist.
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Miller replied that Bannon's role "has been greatly exaggerated, whereas the president hasn't gotten the due that he deserves". Steve Bannon has expressed regret over his Trump tales, following a war of words with the United States president.
There is also uncertainty over whether former champions Novak Djokovic, Stan Wawrinka and Rafa Nadal, the latter of which arrived in Melbourne earlier on Friday, will be fit to take to the court.