Another worrying sign for Nick Kyrgios's chances of playing in the Australian Open as two HUGE stars plan comeback Down Under

More than half of the top 50 female players in the world will kick off their Australian Open preparations at the Brisbane International, but Australian star Nick Kyrgios is a notable absentee in the men's draw with the offer of a wildcard entry still standing.

Amid ongoing doubt about when and were Kyrgios will return to the court, Brisbane officials have left the door open for the 2022 Wimbledon finalist to play as a wildcard in the event where nine grand slam champions across the men's and women's draws will take part.

Former world No.1 and 22-time grand slam event winner Rafael Nadal has committed to making his own injury comeback in Brisbane when the event starts on December 29, while two-time Australian Open winner Naomi Osaka will also return to action in the event en route to a Melbourne Park return.

But current men's No.2 Carlos Alcaraz was another notable absentee from the list with his preparation plans for the Australian Open unclear.

But it's unlikely Kyrgios will play with Davis Cup stars Alexei Popyrin, Max Purcell and Jordan Thompson to fly the Australian flag in the men's singles and Gold Coast's Kimberly Birrell getting a wildcard into the women's singles main draw.

'Nick is a day by day proposition at the moment. I think he said that himself,' tournament director Cam Pearson said.

'Hopefully he will share his January plans very soon. We've got a couple of wildcards left and selectors have a big decision. 

'There are a number of Aussies that are vying for those two wildcards. If Nick is fit, hell certainly be one of them. 'He's coming back from some serious surgery and has to do what's right for his preparation.'

The women's draw will feature eight of the world's top 20, including world No.2 and reigning Australian Open champion Aryna Sabalenka, and four of the men's top 20, with world No.1 Novak Djokovic committed to playing in the United Cup for Serbia.

'We are thrilled so many of the world's best players want to come to Brisbane,' Pearson said.

'This is one of the strongest fields the tournament has seen in both the men's and women's fields.

'To have nine grand slam champions, 12 WTA/ATP top 20 players, along with so many Australian favourites, is great news for the tournament and our fans.'

After confirming he would play in Brisbane, former world No.1 Nadal did his best to lower expectations.

'I think I'm ready, and I trust and hope that things go well and that it gives me the opportunity to enjoy myself on the court,' he said.

'I expect from myself not to expect anything. This is the truth.'

Pearson said Nadal wouldn't be heading to Brisbane unless he was '100 per cent ready'.

'Maybe he's just trying to take a bit of pressure off himself,' he said. 'We can't wait for him to arrive.'