In order to stay where I am - and I want to do that - I have to stay dedicated as well as I have been before I became No. 1.

I know that success does not come at once, it is not a thing achieved overnight. It is the result of many, many, many years of working and trying to achieve goals.

I always try to have something that keeps my mind relaxed, keeps my mind a little bit off tennis.

Messi is the best player on the planet and he keeps on improving at Barça, now the best team in the world. What Messi does on and off the pitch is an inspiration for children who dream of becoming a footballer.

My mother is a special story. She went through so much to bring us up, four men at home, especially when our country was going through really difficult times.

What I learned as a young child continues to have a tremendous impact on my life today.

Tennis is a mental game. Everyone is fit, everyone hits great forehands and backhands.