Will Novak Djokovic, Rafael Nadal and Serena Williams all feature at the Australian Open? Tournament director Craig Tiley is confident the star trio will be in action this month.
There are serious doubts over past champions Djokovic, Nadal and Williams with the year's opening grand slam less than a fortnight away, while Andy Murray is struggling to be ready for the tournament, which already lost former world number four Kei Nishikori to a wrist problem.
An elbow injury has hampered six-time Australian Open champion Djokovic, who was forced to skip the Mubadala World Tennis Championship and the Qatar Open, having not played competitively since withdrawing from the quarter-finals of Wimbledon in July.
World number one Nadal - who lost to Roger Federer in last year's final at Melbourne Park - is battling to overcome a right knee problem, which saw him pull out from the warm-up event in Abu Dhabi, as well as the Brisbane International.
However, Tiley is confident the pair will grace the Melbourne courts, starting January 15, despite their injury concerns.
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"Some of these guys are in the air, heading down here as we speak," Tiley told reporters on Thursday. "Novak has signed to play the Tie Break Tens and he's also got some specific practice matches lined up [at the Kooyong Classic].
"He's already got every hour of the day planned from when he arrives until the start of the Open. So he'll be ready. The same with Rafa, he'll will be ready."
On five-time runner-up Murray, who is struggling with a hip complaint, Tiley added: "It's a day by day thing with him. He's going to stay in Brisbane and keep training. If it goes well, he'll come down to Melbourne. I do expect to see him in Melbourne at the weekend."
Tiley is also confident of seeing 23-time grand slam champion Williams defend her title in Melbourne amid uncertainty over her commitment to play the Australian Open.
Williams made her return to action at the Mubadala World Tennis Championship last month after giving birth in September, losing to Jelena Ostapenko, though she was non-committal over her plans for the upcoming slam.
"I'm in touch every day with her and her management team and she wants desperately to be here," Tiley said. "I still believe she will be [here].
"She has made it very clear to me that this is her favourite event and that's why she will do everything she possibly can to be here. Her whole life revolves around getting ready for the Australian Open right now.
"I'm pretty confident in my communications that she wants to be here - and when Serena wants something, she normally gets it.
"I think it's just her assessing whether she's ready to play. She wants to win the Australian Open, to beat the record, she's just focused on grand slam titles. I think if she felt she was healthy enough to compete, to play seven tough, two- or three-set matches over the course of two weeks, she'll be here. That'll be her own decision."