Roger Federer is No. 1 in natural talent, Rafael Nadal is the best in mental preparation: Andrey Rublev

World No. 8 Andrey Rublev believes Swiss legend Roger Federer's natural talent and Rafael Nadal's mental strength are the qualities that set them apart.

Roger Federer and Rafael Nadal are tied at 20 Grand Slams each - the most by any player in men's tennis history. They are both widely considered to be contenders for the title of 'Greatest of All Time' or 'GOAT', along with 17-time Slam winner Novak Djokovic.

The 22-year-old Rublev has played Federer and Nadal on one occasion each so far, with a 1-0 record against the Swiss superstar and a 0-1 record against the Spanish legend. In an interview with the Russian website Sport Express, Rublev spoke about the contrasting qualities that the two superstars are the best at.

"For me, Rafa Nadal is the best athlete in the world in terms of psychological preparation," the Russian said. "In terms of natural talent, Roger Federer is the number one player I've ever seen."

Rublev, who has won four ATP titles in 2020, defeated Roger Federer in their only encounter at the 2019 Cincinnati Masters in straight sets. After that match, Federer heaped lavish praise on the Russian for his performance.

Andrey Rublev (+700) defeats Roger Federer in straight sets at Cincinnati...Roger's last tuneup before the US Open 😨pic.twitter.com/CSRej42aXT

— The Action Network (@ActionNetworkHQ) August 15, 2019

"He was super clean. Defense, offense, serving well," Roger Federer had said of Rublev after his loss. "Didn't give me anything. He was everywhere. It was tough for me, but an excellent match by him."

Rublev added that Roger Federer's praise had motivated him, but that he was fully aware of the difference between himself and his peers such as Felix Auger-Aliassime, Alex de Minaur, Denis Shapovalov and Stefanos Tsitsipas at that time.

The Russian was yet to break into the top 20 back then, and had only won one career title.

"It's incredibly nice when such a great player compliments you," Rublev said. "But at that moment, I was not ranked so high. Many of my peers were much higher than me, and even younger guys, such as Felix Auger-Aliassime and Alex de Minaur, came close. And Stefanos Tsitsipas was already firmly established in the top 10 then."

"So I realised that I still had to work and work to try to get closer to the top 10," he added. "I understood the level of Tsitsipas, Shapovalov, Auger-Aliassime... It was hard for me to play with them. Even when I played good tennis, I could easily lose to them in two sets. Now I am confident that if I can play my game, then I will have many chances to win, to control the course of the match. Last year, I did not feel this way."

I can only say positive things about Roger Federer: Andrey Rublev on the Swiss' down-to-earth attitude

Andrey Rublev celebrates after beating Roger Federer at the 2019 Cincinnati Masters

Rublev feels Roger Federer is very easy to talk to despite his incredible success and fame, although he has a mostly professional rapport with him.

"I can only say positive things about Roger Federer," the 22-year-old said. "He is one of the best tennis players in history, yet he is very easy to talk to. He emits only positive (vibes).The communication (with him) is mostly normal: 'How are you?', 'How was your match?', 'Did you manage to have a rest?' Nothing more."

The Russian added that he shares a similar relationship with Rafael Nadal, with whom he had trained with way back in 2014 - when he was a rising junior.

Andrey Rublev shakes hands with Rafael Nadal after their quarter-final at the 2017 US Open

"With Rafa , the level of communication is about the same as with Roger," he went on. "Perhaps, if I had taken the initiative, they would have shared some advice with me. But all I wanted to know was there in their interviews. For example, Nadal constantly explains how he tunes in for matches. So there are no secrets."

Rublev, whose tally of 37 wins this year is the joint highest on tour along with World No. 1 Djokovic, is currently in line to qualify for one of the two remaining berths in the season-ending ATP Finals at London. If he does get there, it would mark his debut at the tournament.

#6 the most special one for me🖤 Thank you for the support at @formula_txСпасибо всем за поддержку🇷🇺 #saintpetersburg pic.twitter.com/lwnCNd6Oem

— Andrey Rublev (@AndreyRublev97) October 19, 2020