The Spaniard beat Pablo Cuevas in the third-round of the tournament with heavy strapping on his knee, but then announced he would be unable to play the Serbian qualifier Filip Krajinovic in the next round.
The ATP Tour Finals begin in a week's time, but Rafa fans are urging their hero to let his knee heal and not push himself to compete. "But unfortunately, it was impossible for me to return to the court in the same condition as last night", Nadal said.
"Yesterday, the pain during the match was too much". The 31-year-old hasn't confirmed if he will compete, but is set to travel to London on Wednesday.
Nadal has fought back this year from a series of injuries, winning the French and US Open titles.
"For me it's not about London". Federer is 36, while is long-term rival Nadal is five years his junior.
Building on his resurgent competition success this year, Nadal approached attaining the No. 1 ranking with his customary fearlessness, prioritizing the Asian post-grand slam season, a time where he's generally been less successful.
Nadal started this season ranked No. 9 in the world, but a resurgent year-in which he has won the French Open and the U.S. Open and reached the Australian Open final-will see him end 2017 as the world No. 1, even if he has played his last match. "It's not the thing that I love to do".
He added: "Of course it [withdrawal from Paris Masters] is a very tough decision for me, especially here in Paris, which has been the most important city in my career without a doubt".
The player didn't confirm his participation in the ATP Finals next week, a title that has eluded him so far.