(Reuters) - Aged just 19, men's Miami Open tennis finalist Jannik Sinner already stands out on the ATP tour for a calm demeanour belying his youth - something his coach Riccardo Piatti puts down to the Italian's background as a junior ski champion.
In February, Sinner became the youngest man since Novak Djokovic in 2006 to win two ATP titles, and a win in his first ATP Masters 1000 final on Sunday against friend and occasional doubles partner Hubert Hurkacz would make him the youngest-ever Miami winner.
After his Miami quarter-final loss to Sinner, Alexander Bublik asked the Italian at the net if he was human, while former world No. 9 Roberto Bautista Agut also lauded Sinner for his mental strength after losing to him in the semi-final.
A former junior champion in giant slalom, Sinner switched his entire focus to tennis when he moved to coach Piatti's academy in Bordighera from San Candido as a 14-year-old. Sinner said this week he used to play tennis only twice a week before moving to Bordighera.
"If you ski or make some race, you understand immediately that you need to be concentrated and if you make a mistake, you are out," Piatti told the ATP Tour website http://www.atptour.com.
"He liked tennis because he can make a mistake and then immediately come back and play again. I saw that he was playing well, but what took my attention was outside the court.
"He was a 14-year-old kid, but he controlled the mind of a young man of 17, 18, 19 ... he was quite mature."
Sinner will jump to a career-best ranking of No. 14 if he wins the Miami title, but Piatti said Sinner's ambition was higher - claiming Grand Slams and the No. 1 ranking.
"(The final is) an important moment, but not the last moment. It's part of what he needs to do," Piatti said.
"Federer when he won Milan the first time is not the Federer playing now and it's the same for Djokovic and Rafa (Nadal). They're improving a lot and they are changing a lot. I think Jannik has this kind of potential."