Carlos Alcaraz’s hopes of making up ground on Novak Djokovic in the race for year-end world No. 1 have taken another setback.

After going 5-2 on his first trip to China that ended with a round-of-16 loss to Grigor Dimitrov at the Rolex Shanghai Masters, Alcaraz stood 500 points behind the 24-time major winner. On Wednesday, the 20-year-old announced he had pulled out of Basel due to a pair of physical problems—an event that would have allowed Alcaraz to make up exactly 500 points had he emerged as the champion.

“Unfortunately I will not be able to play in Basel this year! I have a problem with the plantar fascia in my left foot and muscle fatigue in my lower back which need treatment so I can play the rest of the season. I hope to see you all soon!” Alcaraz wrote on his Instagram.

The Spaniard, who became the first teenager in ATP history to end a season at No. 1 last year, is 63-9 in 2023 with six titles to his name. Alcaraz’s biggest triumph came at Wimbledon when he edged out Djokovic in five sets to celebrate his second Grand Slam trophy. The Serbian had previously taken their Roland Garros semifinal encounter and later won an instant classic to clinch their Cincinnati final blockbuster.

Djokovic is expected to play his first tournament since winning the US Open when the final Masters 1000 event of the season launches in Paris-Bercy at the end of this month. The 36-year-old went 27-1 at the majors this season, accounting for 60 percent of his match wins on the year. It was also revealed Wednesday that Djokovic will team up with compatriot Miomir Kecmanovic in doubles at the Rolex Paris Masters.