Anything can happen. It's a Grand Slam.
Whilst Federer faces Slovenian Aljaz Bedene next week, top seed Nadal, the losing finalist past year, is up against Dominican Victor Estrella Burgos. "I don't want to know who I play other than just seeing the sheet at the end and knowing who my first-round opponent is".
Yet amid it all Federer keeps going, winning all his matches at the mixed-teams Hopman Cup in Perth this month and seemingly injury-free.
While there are many major sporting events that grace the stadiums and streets of the Victorian capital of Melbourne, Australia, none have a bigger impact on the city than the Australian Open.
In the quarter-finals, Federer could run into Juan Martin del Potro, who is set to return to the top 10 or ATP World Tour Finals runner-up David Goffin.
The 2014 victor Stan Wawrinka, who hasn't played since last year's Wimbledon and subsequent knee surgery, has had little warm-up work and is no longer with his four-year coach Magnus Norman.More news: Sarah Sanders gives press briefing
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Another Australian who has enjoyed a strong build-up to the year's first Grand Slam is Ashleigh Barty.
Djokovic had a contrasting 2017, starting at No. 2 but losing in a second-round upset at the Australian Open and not playing again after Wimbledon.
The former Wimbledon finalist's ranking has slid to 83 after making a first-round exit a year ago in 14 tournaments including Wimbledon and the US Open.
Last year's women's singles champion, Serena Williams, won't compete after giving birth to her first child in September.
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"There's no easy way to get to the top", Sharapova told the crowd at Margaret Court Arena before the draw. 19-time major champion Roger Federer has been given the number two spot, Grigor Dimitrov at three, followed by Alexander Zverev and Dominic Thiem who completes the top five. I don't say I'm at 100 per cent - I can only say that when I get the feel of a tournament.
"The drive, I still have it. I expect to continue to do so". "For me it was not ideal to not be in Brisbane, I would have loved to be there but I had to make a different schedule this year", Nadal said during the week.