'S***, this guy's a pain!' recounts Rafael Nadal on his sessions with Uncle Toni

Rafael Nadal has revealed that he did not like his Uncle Toni's training methods as a kid as they were too strenuous but understood that they were for his own benefit. The Spaniard went on to win 16 Grand Slams in his career, something he believes would not be possible but for his Uncle's tactics.

Toni decided to take some time off and brought an end to his association with Rafael earlier this year, after a period which has been one of his most fulfilling experiences in his 27 years in the world of tennis. Nadal ended the year with seven titles to his name, including two Grand Slams – the French Open and the US Open.

Rafael and Toni have won everything there is to win – 16 Grand Slams, 30 Masters Series titles and two Olympic gold medals in the singles and doubles events – making it a career Golden Slam.

Rafa is only the second men's singles player to do it, with Andre Agassi being the other.

The Spaniard added that there were few people on the planet who would want him to succeed more than Toni but joked that the sessions were tense which made him lose his temper at times.

"Look, he's a friendly guy, but when I was younger there were times when because of his desire for me to do things well training sessions were tense. Although I always knew very well that he was doing it for my own good," Nadal said, in an interview with AS.

"And I know that there are few people who could have wanted things to go well for me more than he did. That doesn't mean that weren't moments when I thought: "Shit, this guy's a pain!" But when my temper cooled down I always understood that he was doing it all for me."

On if Toni was the right man to be at his side, Nadal was without doubt in his verdict, saying that the spirit and character he shone with him was a crucial factor in his success. The Spaniard added that Toni remains the most important person in his life.

"I couldn't have ever asked for someone better to have at my side, because the spirit and character I have had on the court, and a lot of the tough situations I have come through, were because of those times we experienced together and during which he helped me to grow as a person and an athlete," he added.

"I can't say how grateful I am for everything he has done for me. He's the most important person in my career."