Seven-times major singles champion Venus Williams has joined men's world number one Carlos Alcaraz in withdrawing from the Australian Open due to injury.

Williams was set to play her 22nd Australian Open after being awarded a wildcard to the tournament, which begins at Melbourne Park on January 16.

The 42-year-old American — who is a two-time Australia Open finalist — was preparing for the Australian Open at the Auckland Classic.

"Venus Williams has withdrawn from the Australian Open due to an injury sustained at the ASB Classic in New Zealand," the Australian Open said in a tweet.

Australia's Kimberly Birrell was awarded Williams's wildcard place in the main draw.

Earlier on Saturday, it was confirmed that Alcaraz would miss the Australian Open because of a leg injury.

The 19-year-old Spaniard — who won his first major singles title at the US Open in September — revealed he suffered a muscle injury in his right leg during pre-season training.

"I had worked a lot to reach my best level in Australia. Unfortunately, I won't be able to play either Kooyong (a warm-up event) or the Australian Open," Alcaraz posted on social media.

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

Alcaraz's withdrawal means his countryman, reigning champion Rafael Nadal, will be promoted to top seed for his title defence at Melbourne Park.

Reuters/AAP