Carlos Alcaraz has sustained a leg injury in pre-season training, forcing him to miss the Australian Open ©Getty Images

World number one Carlos Alcaraz of Spain has been ruled out of the Australian Open with a leg injury.

The Spanish teenage sensation has revealed that he has sustained an injury to the "semimembranosus muscle in my right leg" while training.

Alcaraz had been due to play in next week’s Kooyong Classic in Melbourne before the Australian Open, scheduled to start in nine days' time.

However, Alcaraz has now confirmed that he will be unable to compete in either tournaments following the injury setback.

"When I was at my best in preseason, I picked up an injury through a chance, unnatural movement in training," Alcaraz wrote on Twitter.

"This time it’s the semimembranosus muscle in my right leg. 

"I’d worked so hard to get to my best level for Australia but unfortunately I won’t be able to play the Care A2+ Kooyong or the Australian Open.

"It’s tough, but I have to be optimistic, recover and look forward. 

"See you in 2024 @australianopen."

Alcaraz became the youngest men’s singles world number one after winning the US Open in September at the age of 19.

An abdominal muscle tear sustained in early November forced Alcaraz to miss the ATP Finals as his 2022 came to an end.

Alcaraz played an exhibition event in the United Arab Emirates last month only to pick up another injury in training.

His absence in Melbourne means fellow Spaniard and reigning Australian Open champion Rafael Nadal is poised to be top seed for the first Grand Slam of the year.

Serbia's Novak Djokovic, a nine-time winner of the Australian Open, is another favourite for the title.

There are also injury concerns for women's singles world number one Iga Świątek before the Australian Open.

The Polish three-time Grand Slam champion has withdrawn from the Adelaide International 2 tournament because of a shoulder problem.

Britain's Emma Raducanu, the 2021 US Open winner, is a doubt for the Australian Open after rolling her ankle in the ASB Classic in Auckland, while 42-year-old American great Venus Williams has sustained an injury at the same tournament.

Williams, a seven-time Grand Slam champion, was due to play at the Australian Open after receiving a wildcard but has now pulled out.