See the worrying sign Nick Kyrgios won't play in the Australian Open

Australian Open boss Craig Tiley has significantly softened his language on Nick Kyrgios' likely availability for the tournament, casting doubt over whether the star will take the court in January.

Tiley said last month he 'fully expected' Kyrgios to play in January but told reporters on Thursday the 28-year-old would need to consider what was best for his health with the full 2024 season ahead of him.

Kyrgios only managed a single match in 2023 after withdrawing from all four grand slams due to a lingering knee injury and a torn ligament in his wrist ahead of Wimbledon.

His world ranking has slid out to 192, with Tiley suggesting the explosive star would be granted a wildcard if he was fit to play.

'We have spoken to Nick, and he obviously wants to do the best he possibly can to give him the best chance to play in January ... Nick's position will be determined closer to the event,' Tiley said.

'I think whatever gets him the best chance to progress during the year ... we have wildcard exchanges with the French and Wimbledon, so there's an opportunity to really help an Australian player not just have one tournament to go into but several, so we'll weigh that all up to make a decision - we've got wildcards to do that.

'Whether he's playing, whether he's doing something else, Nick will be here in January and to get him to play will be great, but we've got to take it as it comes and he's got to take care of his health ... because he's not just got January, he's got the entire year (ahead) too.'

Tiley said Rafael Nadal still looked set to take his place in the men's draw as he recovered from arthroscopic hip surgery in June.

'Rafa has been training, I follow him closely, probably every day, because he's a massive drawcard for us,' he said.

'He wants to play, he's obviously planning on playing ... I'm certain Rafa will be here because he's not going to want to miss the opportunity to repeat what he did a couple of years ago.'

The Australian Open will include an extra day's play in 2024, beginning a day earlier on Sunday, January 14 in a bid to reduce the number of late finishes early in the tournament.

Tiley said the extra day to schedule the first round would mean one less match on each court during the day session and more games played with protection from the weather on the covered courts, but he conceded little could be done to stop hard-fought matches after the first round carrying on into the early morning.

'It's a significant mitigating measure, but it doesn't guarantee that there won't be late finishes too,' he said.