Madrid, Spain, Jan 7 (IANS): World No. 1 Carlos Alcaraz has withdrawn from the Australian Open due to a right leg injury.

The 19-year-old Spaniard, who last year became the youngest player to finish year-end No. 1 in the Pepperstone ATP Rankings, would have held the top seed at a Grand Slam tournament for the first time in his career.

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

The withdrawal imperils Alcaraz's hold on World No. 1, with Casper Ruud, Stefanos Tsitsipas and Novak Djokovic all having an opportunity to rise to top spot the Monday after the Australian Open.

Despite his breakout season, Alcaraz had a frustrating end to 2022, being forced to withdraw from the quarter-finals of the Rolex Paris Masters with an internal oblique muscle tear that also sidelined him at the Nitto ATP Finals in Turin.

On September 12, Alcaraz became the youngest World No. 1 in the history of the Pepperstone ATP Rankings. He finished 2022 with a 57-13 record and five tour-level titles, including his first two ATP Masters 1000 victories (Miami and Madrid) and his first Grand Slam trophy at the US Open.

Last year Alcaraz lost 7-6 in the fifth set to Matteo Berrettini in the third round of the Open.