Chiudinelli, a retired tennis player, grew up with Federer in Switzerland and ended up representing his country alongside the 19-time Grand Slam winner in the Davis Cup.

But the 36-year-old never reached the same heights as Federer, hitting a career-high of No 52 in the world.

However, he has remained close friends with the world No 2 and insists he remains a grounded individual.

“[Our relationship] is like a normal friendship,” Chiidinelli told Swiss newspaper BZ Basel.

“Most important is the honesty. Trust too, and reliability.

“Roger has not been changed by the great success and has remained with his feet on the ground.

“That's not put on, it's real.

“We do not meet often, but when we do, we have a good time together.”

Chiudinelli hung up his racket earlier this year after losing to Robin Haase on home soil at the Swiss Indoors, citing an “injury-plagued year” in which he had been “rarely [able to] play up to his full potential”.

And Federer himself was court-side to watch his last match, emotionally embracing his friend after the defeat.

“It makes me sad because I have been knowing Marco for a lot of time,” Federer said at the time.

“But you should not be sad because we should celebrate his career.

“I am happy that he found this moment. He is not 29 anymore and he can be proud.”

He added: “We spent so much time together. I didn't want to miss this moment.

“In case of a defeat this would be Marco's last match...I needed to be here.”