A new Australian Open champion will be crowned this after 2017 winner Serena Williams withdrew from the season opening Grand Slam, saying she is not ready to return to tournament tennis.

Williams was pregnant with her first child when she won last year’s tournament at Melbourne Park to claim the 23rd Grand Slam singles title of her career. She gave birth to her daughter, Alexis, in September.

Williams played in an exhibition tournament last week in Abu Dhabi and had indicated after her loss to French Open champion Jelena Ostapenko that she might not make it to Melbourne.

”After competing in Abu Dhabi I realized that although I am super close, I’m not where I personally want to be,” Williams said in a statement released Friday by Australian Open organizers. ”My coach and team always said `only go to tournaments when you are prepared to go all the way’. I can compete – but I don’t want to just compete, I want to do far better than that and to do so, I will need a little more time.

”With that being said, and even though I am disappointed about it, I’ve decided not to compete in the Australian Open this year.” Williams, 36, is a seven-time champion of the Australian Open and needs one more Grand Slam title to tie the all-time record held by Margaret Court.

Her withdrawal comes less than 24 hours after fellow former world No.1 Andy Murray withdrew from the men’s event with a chronic hip injury.

Several other big names, including top-ranked Rafael Nadal, six-time champion Novak Djokovic and 2014 winner Stan Wawrinka, also are dealing with injuries.

The Australian Open serves off January 15.