Rafael Nadal has pulled out of next month's season-ending World Tour Finals because of a longstanding left knee injury.
The Spaniard, who hasn't played since June, will also miss next week's Paris Masters.
The 26-year-old Nadal says "it doesn't come as a surprise. I will hopefully resume my tennis practice soon since I am making good progress with my recovery from injury."
The French Open winner, an 11-time Grand Slam champion, has said he hopes to return in time for January's Australian Open. He is scheduled to play at an exhibition event in Abu Dhabi at the end of December.
Only the ATP's top eight players reach the Nov. 5-12 World Tour Finals in London, and the fourth-ranked Nadal had already qualified.