In the third part of our exclusive serialisation of his autobiography Rafael Nadal talks about the complex, tense relationship with his coach in our final exclusive extract from his autobiography
My uncle Toni was the resident coach at the tennis club in our home town, Manacor. The clubhouse was what you'd expect in a town of barely 40,000 people: medium-sized, dominated by a restaurant, with a terrace overhanging the clay courts.
One day I joined in with a group of half a dozen children Toni was teaching. I was already crazy about football, playing on the streets with my friends every spare moment my parents let me .
I liked being part of a team and Toni says that at first I found tennis boring. But learning in a group helped, and it's what made possible everything that followed. If it had just been me and my uncle, it would have been too suffocating. It wasn't until I was 13, when I knew my future was in tennis, that he began training me on my own.
Toni was tough on me right from the start, tougher than on the other children. He demanded a lot of me, pressured me hard. He'd use rough language, shout a lot, he'd frighten me — especially when the other boys didn't turn up and it was just the two of us. If I saw I'd be alone with him when I arrived for training, I'd get a sinking feeling in my stomach.
My friend Miguel Angel Munar reminds me sometimes how Toni, if he saw my head was wandering, would belt the ball hard at me, not to hit me, but to scare me, to startle me to attention.
It was always me, too, who he got to pick up the balls, or more balls than the others, at the end of the training session; and it was me who had to sweep the courts when we were done for the day. Anyone who might have expected any favouritism was mistaken.
Quite the opposite. Miguel Angel says Toni bluntly discriminated against me, knowing he could not have got away with it with him and the other boys but with me he could, because I was his nephew.
My mother remembers that, as a small child, sometimes I'd come home from training crying. She'd try to get me to tell her what the matter was, but I preferred to keep quiet.
Once I confessed to her that Toni had a habit of calling me a "mummy's boy", which pained her, but I begged her not to say anything to Toni, because that would only have made matters worse.
Toni never let up. Once I started playing competitive games, aged seven, it got tougher. One very hot day I went to a match without my bottle of water. I'd left it at home.
He could have gone and bought me one, but he didn't. So that I'd learn to take responsibility, he said. Why didn't I rebel? Because I enjoyed tennis, and enjoyed it all the more once I started winning, and because I was an obedient and docile child. My mother says I was too easy to manipulate.
Maybe, but if I hadn't loved playing the game, I wouldn't have put up with my uncle. And I loved him too, as I still do and always will. I trusted him, and so I knew deep down that he was doing what he thought was best for me.
I trusted him so implicitly when I was little that I even came to believe he had supernatural powers. It wasn't till I was nine years old that I stopped thinking he was a magician capable, among other things, of making himself invisible.
During family get-togethers my father and grandfather would play along with him on this, pretending to me that they couldn't see him. So I came to believe that I could see him but other people couldn't.
So there was fun in my relationship with Toni, even if the prevailing mood when we trained was stony and severe.
And we had plenty of success. If he hadn't made me play without water that day, if he hadn't singled me out for especially harsh treatment when I was in that group of little kids learning the game, if I hadn't cried as I did at the injustice and abuse he heaped on me, maybe I would not be the player I am today.
He always stressed the importance of endurance: "Endure, put up with whatever comes your way, learn to overcome weakness and pain, push yourself to breaking point but never cave in. If you don't learn that lesson, you'll never succeed as an elite athlete." He did a lot to build that fighting character people say they see in me on court.
There's a fine balance in the tension that my uncle's presence in my life creates. Usually, as the record shows, it's been a positive, creative tension.
Sometimes he doesn't measure his words well and the effect is to sour, rather than to enhance, my mood, which in turn impacts my game.
A trivial example of the sort of thing I have to put up with would be this: we are at a hotel somewhere in the world and we agree to meet downstairs in the car at a certain time to go to training. He arrives 15 minutes late, but I don't say anything. But the next time I arrive 15 minutes late for an appointment, he complains that we can't carry on this way.
Another example. During a match I'll hear him say, "Play aggressive!" before a return of serve . I'll go for it, the ball will go out, and then he'll say, "Now wasn't the moment".
But it was the moment; it just happened that I messed up the shot. If the ball had gone in, he'd have said, "Perfect!" The atmosphere in our team is tenser when Toni's around than when he's not.
What I never lose sight of is that, on balance, that tension benefits my game. Nor do I forget that he wouldn't generate such a response in me, be it for good or for bad, if I didn't feel a tremendous respect for him.
When I am hard on him, it's because I believe he asks for it.
But one thing must be clear: if we have fights, they are to be taken in the context of a mutual trust and a deep affection built up over many years of being together.
Everything I have achieved in the game of tennis, all the opportunities I have had, are thanks to him. I'm especially grateful to him for having placed so much emphasis from the very beginning on making sure I kept my feet on the ground and never became complacent.
While Toni's refusal to let me off the hook has its value, in that he pushes me always to improve and do better, it can also be bad because he creates insecurity.
I often feel this way, especially in the early rounds of a tournament, and the truth is that while he deserves credit for so many good things in my career, he also deserves blame for me being more insecure than I ought to be.
The point is to hold on to the lessons I've absorbed from Toni but to impose my own judgment more, striving to find the right balance between humility and overconfidence.
Sure, you must always respect your rival, always consider the possibility that he might beat you, always play against the player ranked 500 in the world as if he were ranked No 1 or 2. Toni has helped me to have this very clear in my mind, maybe too clear.
What I am trying to teach myself now is to tilt the balance the other way, to exercise more autonomy over my life and disagree more openly with him. This may be a consequence, in part, of me seeing that Toni has his doubts and insecurities too; that he contradicts himself often; that he is not the all-knowing magician of my childhood.
These are edited extracts from 'Rafa: My Story' by Rafael Nadal with John Carlin, published by Sphere (RRP £17.99). It is available from Telegraph Books for £16.99 plus £1.25 p&p. Please call 0844 871 1515 or go to books.telegraph.co.uk