If he is to fall at the first hurdle, it could mark the sad end the career of arguably Britain's greatest ever sportsman, Sir Andy Murray. The men's side of the Aussie features 128 participants, which shakes out to seven rounds of scintillating tennis action over two weeks, culminating in the Final on Sunday, January 27 (more like early Monday morning).
Murray has won three Grand Slam titles, having reached a major final eleven times.
"He is someone who simply never gets tired".
Late in 2017, Federer took part in Murray's charity exhibition event in Glasgow, and remembers how much the three-time grand slam champion was struggling. He's targeting retirement at Wimbledon. "It's just now that it's definite", he added, acknowledging that the era of the "Big Four" 1 himself, Djokovic, Rafael Nadal and Murray was drawing inexorably to a close. "I tried pretty much everything that I could to get it right - that hasn't worked".
"It's sad for me, but for all sport, because Andy is a very respected and likable guy around the locker room, " Djokovic said.
"He's a good guy, Hall of Famer, legend".
"It's a tough one, but one down the road he can look back on and be incredibly proud of everything he has achieved".
Murray is due to play Spain's Roberto Bautista Agut in the first round of the Australian Open on Monday - a match which may turn out to be his last. "You can always focus on the negatives", Djokovic replied.
"I wasn't, no. To be honest, I wasn't, " top-ranked Djokovic said.
Tim Henman paid tribute to Andy Murray for an "incredible" career and explained that his fellow Briton will not want to keep playing just to make up the numbers, amid his impending retirement.
"I think he has been enjoying being a spokesman in the game and now he has a reputation as encouraging women into sport and into coaching. I've always been focused on tactics and winning and finding a way".
Wozniacki has the first of the night matches on Rod Laver against Alison Van Uytvanck after a day session on the main stadium that features Maria Sharapova, Nadal and No 2-ranked Angelique Kerber.
"I also think that some people have some personal interest for sure".
"To be here as the defending champion, I'm just taking it as a nice, fun challenge". 'Thinking about what I do when I finish playing and rushing into decisions - from speaking to psychologists - is the worst thing I should be doing. "I feel like I'm hitting the ball well".
The Romanian said she was untroubled by the back injury that curtailed her 2018 season and was mentally stronger as a result of last year's loss in the decider. Now she's back on the tour, seeded 16th, aiming for an eighth Australian title.
The Big Four have dominated the men's circuit for more than a decade and shared around the major titles with few exceptions, such as Stan Wawrinka's wins at the 2014 Australian Open, the 2015 French and the 2016 U.S Open, and Marin Cilic's victory at the 2014 U.S. Open.