World number one Carlos Alcaraz is out of the Australian Open after suffering a leg injury in pre-season training.

He had been due to play in the Kooyong Classic next week before the Australian Open begins on 16 January.

"When I was at my best in pre-season I picked up an injury through a chance, unnatural movement," Alcaraz said.

"I'd worked so hard to get to my best level for Australia but unfortunately I won't be able to play the Kooyong or the Australian Open."

He added: "It's tough, but I have to be optimistic, recover and look forward. See you in 2024 Australian Open."

Alcaraz became the youngest man to hold the world number one position following his victory over Casper Ruud in the US Open final in New York four months ago.

His absence at the Australian Open means compatriot and defending champion Rafael Nadal is set to be the men's top seed at Melbourne Park.

An abdominal injury ruled Alcaraz out of the season-ending ATP Finals and Davis Cup towards the end of 2022.