Rafael Nadal admits it is unlikely he will emulate great rival and friend Roger Federer and play into his 40s.
Nadal, 36, gets his Nitto ATP Finals campaign underway in Turin against Taylor Fritz on Sunday as he eyes his first success in the competition, 17 years after he first qualified back in 2005.
He has overcome a series of injury problems over the course of his career and insists he is still enjoying his tennis as he enters the twilight of his career. Asked if he will follow in the footsteps of Federer, who retired at 41 earlier this year, Nadal told reporters: "I don't know, I can't predict the future.
“It looks difficult, honestly, but at the same time, when I was 28 or 29, for me was super difficult to imagine myself playing at the age of 36, and here we are - In a high position on the ranking and being competitive.
“You never know what can happen. It always depends on different facts; some of them you are able to control, and others you don't have the chance to control.
“So, let's say I am super happy to be where I am at the age of 36 and a half. Let's see, I just want to keep going and enjoy the fact that I am playing every year, which, for me, is a present."
Despite his 22 Grand Slam victories, Nadal is yet to win the ATP Finals and added: "It’s a great feeling to be here after I first qualified in 2005. I'm super happy because it means I had a very positive season in terms of possible results.
“I'm not a fan of talking about what could happen or not. I'm just here to follow my way, try my best every day in every practice.
“Then I have the competition that I'm going to start on Sunday. Then let's see, of course, I'm here to try to achieve the best result possible.”