Roger Federer may be considered one of the greatest tennis players of all time, but the 20-time Grand Slam champion has revealed the obstacles he had to face during his time as a junior.

Speaking to BecomingX, an organisation started by Bear Grylls to showcase the stories of influential stars to help inspire people around the world, the athlete spoke about his doubts over making it professional.

The 39-year-old opened up about his challenges as a junior and the hardships he faced as he played tennis away from home at such a young age.

Federer recounts the first game he played, which he lost 6-0, 6-0, and was doubting his talent.

“I kept on practicing hard, I started playing more tournaments,” Federer said.

“I started to become very successful also, even as a junior, at least in my area. Nationally, I became Junior Swiss Champion for the first time when I was 12 years old.”

But a few years later, Federer left his family to join the National Tennis Centre in Switzerland.

The Swiss maestro said he became very homesick during this period.

“And off I went at 14 to the National Tennis Centre. I was in a great family from Monday to Friday and then I would only come home on the weekends, and I'd be incredibly homesick for the first nine months,” he added.

“Results dropped, I lacked confidence, couldn't speak the language, I really struggled.”

Federer says those years shaped who he has become today.

“It was quite a rough journey,” Federer said.

“I think those were the two most influential years of my life, from 14 to 16. Being away from home, persevering and having that responsibility to figure out the things, sort of on my own sometimes.”

But Federer also owes his success to his former mentor Peter Carter, who died in a car accident in 2002, a tragedy which changed Federer’s life forever.

The Swiss maestro said the tragedy prompted him to “switch gears” and take tennis more seriously.

“When I was 16, Peter Carter joined the NTC and he became my mentor,” Federer said.

“If I play the way I play today, it's probably because of Peter.

“Obviously, the news totally shocked me and rocked my world.

“In some ways, it was truly a wake up call.

This is when I guess I shifted gears and I was just like let's get serious about tennis, very serious.”

Federer took a back seat in 2020 and announced he would be sitting the remainder out, after the Australian Open, due to a knee injury.

This article originally appeared on Over60.