World No. 3 Rafael Nadal will undergo appendix surgery in November and will miss the remainder of the season, he said on Friday.
The Spaniard will miss the Paris Masters and the ATP World Tour Finals in London.
Nadal, who played at the Swiss Indoors this week, cited personal reasons for his withdrawal and said he decided not to play in Paris and London a week ago. He was upset by Croatia's Borna Coric in the quarterfinals on Friday. Nadal added that antibiotics made it too dangerous for him to remove his appendix earlier.
Nadal missed three months from July to September with a wrist injury following a fourth-round loss at Wimbledon.
The 14-time Grand Slam winner has won four tournaments this season: the Qatar ExxonMobil Open, the Rio Open 500, the Matua Madrid Open and the French Open. The victory at Roland Garros was his ninth title in the past 10 years at the Grand Slam event.
U.S. Open champion Marin Cilic has also pulled out of the Paris Masters due a right arm injury.
Ernests Gulbis also withdrew, citing a right shoulder injury.
The Paris Masters starts on Monday.
- Paul Palladino and Chris Johnson