Serena Williams withdraws from Australian Open

Serena Williams will not defend her Australian Open title, after all.

After returning to the court to play an exhibition match in Abu Dhabi last week following a nearly year-long maternity leave, Williams - who gave birth to daughter Alexis Olympia in September - determined she wasn't at the physical level she needed to be to win a Grand Slam title.

"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.

"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.

"The memory of last year's Open is one that I will carry with me, and Olympia and I look forward to coming back again. I appreciate the support and understanding of my fans and everyone at the Australian Open."

Williams was pregnant with Alexis Olympia when she won her Open-era-record 23rd major - and her seventh Aussie Open title - over sister Venus in Melbourne last year.

In Abu Dhabi, Serena split two sets with reigning French Open champion Jelena Ostapenko, before losing the decisive super-tiebreak 10-5.