Rafael Nadal says he does not remember "playing without pain" but has no plans on retiring from tennis anytime soon.
The 20-time Grand Slam champion has had several injuries during his career, including this year when a back problem forced him to withdraw from the ATP Cup.
He played at the Australian Open – reaching the quarter-finals – but withdrew from the Rotterdam Open this week due to the back issue.
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"Honestly, I don't remember ever playing without pain,” the 34-year-old told Brazilian magazine Veja.
In the past few years, I have been experiencing pain more often, and you need to learn to live with it, as long as it doesn't stop you from playing.
"I had to change a lot in my game and in my training. I changed routines, trained less hours than I would like, improved my serve and my positioning. Everything evolves, one way or the other."
Nadal is next set to play at the Miami Open later this month before turning his attentions to the clay season and the chance of winning his 21st Grand Slam title at the French Open.
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Despite his continuing injury issues, he says he does not have any plans of retiring soon.
"As long as I am healthy and able to compete, I intend to enjoy my life in tennis and always give 100 per cent. That's how I see the sport.
In tennis, there is always room for improvement. Over the years, more wisdom and experience come, but at the same time, the physical side is different, which means that we have to rethink the intensity of training and matches. I’ve seen it happen over and over again in tennis. Ultimately, the important thing is to stay healthy for as long as possible.
The world No 2 altered his serve in the early rounds of the Australian Open in a bid to protect his back, but said he was feeling better as the tournament progressed.
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He looked set to make the semi-finals as he led Stefanos Tsitsipas by two sets to love, only to lose in five. With Novak Djokovic winning the tournament to secure his 18th Grand Slam, he is now just two behind Nadal and Roger Federer in the all-time standings.
Whether he remains on top or not, Nadal says his achievements over the last 15 years cannot yet be fully assessed.
When my career is over, we will have enough time to remember my achievements and understand the place I occupy in the history of tennis. I never thought I would win as many titles as I did, so I am very grateful and happy for everything I have achieved in my career. I don't need to get into the discussion about who is the best.
"The most important thing is to be remembered as a good person. In the end, it is the most relevant. The victories, the titles and the memorable moments are important, but everything passes. The person you were is the one who remains forever."
Asked about his relationship with Djokovic and Federer, he added: "I have a great relationship with Roger and Novak. We are rivals only during our matches. The fight takes place only on the tennis court."
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