Novak Djokovic won’t defend his ATP Finals title after ruling himself out on Tuesday due to an unspecified injury.

Djokovic wrote in an Instagram story, “I was really looking forward to being there, but due to ongoing injury I won’t be playing next week. Apologies to those who were planning to see me.”

The year-end, eight-man ATP Finals open in Turin, Italy, on Sunday.

He’s won it a record seven times. Last year he beat current No. 1 Jannik Sinner in the final.

“Wishing all the players a great tournament” Djokovic added: “See you soon!”

Djokovic finishes the year with a 37-9 win-loss record highlighted by winning his first Olympic gold medal in Paris. That was his 99th tour-level title.

He didn’t add to his men’s record 24 Grand Slam titles this year, and after bowing out of the U.S. Open third round, he played only one Davis Cup match and reached the final of the Shanghai Masters last month, losing to Sinner. He then withdrew injured from the Paris Masters.

Besides Sinner, the other ATP Finals qualifiers were Carlos Alcaraz, Alexander Zverev, Daniil Medvedev, Taylor Fritz, Casper Ruud, Alex de Minaur and Andrey Rublev.