Two-time defending champion Novak Djokovic said on Tuesday he will miss the eight-man ATP Finals in Turin due to an "ongoing injury".
"I was really looking forward to being there, but due to ongoing injury I won't be playing next week," Djokovic said on social media.
"Apologies to those who were planning to see me. Wishing all the players a great tournament. See you soon!"
The 37-year-old Serb, currently ranked fifth in the world, sits sixth in "The Race", the ATP's annual rankings to determine the eight competitors at the Finals.
Jannik Sinner, Alexander Zverev, Carlos Alcaraz, Daniil Medvedev and Taylor Fritz have already qualified for the event in northern Italy from November 10-17.
Four players had been chasing the three remaining berths -- Djokovic, Casper Ruud, Alex de Minaur and Andrey Rublev.
Ruud and Rublev are playing in Metz, France this week, with De Minaur in action in Belgrade.