It is the Sunday before the US Open and the rookie Tien is training intensively with his American compatriot, world number 16 Sebastian Korda. Tien’s name is worth remembering. The player from Irvine, California, has had a career year.

Last month, he won his first Challenger title at the Cranbrook Classic, recorded his first match wins on the ATP Tour, and completed a 28-match winning streak between May and July, reaching his highest ever world ranking of 191. And all this at the age of 18.

But as a child, Tien had no plans to pursue a professional tennis career. He had no favorite player and there were no posters of stars in his room.

It was simply a sport that came naturally to Tien from the moment he picked up a racket as a toddler, before fate and his own talent turned him into one of America’s up-and-coming teenage tennis players. Read more about him below.

This article is part of The Next Generation series. While the likes of Roger Federer, Serena Williams and Rafael Nadal are a thing of the past and Carlos Alcaraz and Iga Swiatek are looking at the present, The Athletic explores the next generation: the rising stars tasked with securing the future of tennis.