You see Rafael Nadal train & it scares you, Roger Federer makes you feel stupid when he's playing well: Diego Schwartzman

Roger Federer, Rafael Nadal and Novak Djokovic have ruled the men's tour for nearly 15 years now, winning 58 Grand Slam titles between them. And recently, World No. 9 Diego Schwartzman gave his thoughts about the dominant trio, claiming that they have a few special qualities and that they continue to learn even after they've achieved so much.

"Roger Federer, Rafael Nadal and Novak Djokovic have many things but the most important thing is that they always want to be better," Schwartzman told ESPN. "(Even) today they continue to learn. You see them train and make others better."

.@dieschwartzman: “Federer, Nadal y Djokovic tienen muchas cosas pero lo más importante es que siempre quieren ser mejores. Hoy siguen aprendiendo. Los ves entrenarse y hacen mejores a los demás”.

— Pablo Amalfitano (@AmalfiTenis) March 12, 2021

Diego Schwartzman went on to state that watching a training session of Rafael Nadal can be scary, as the intensity that the Spaniard puts into it is unreal. The Argentine also opined that given Nadal's eagerness to keep improving, he will likely continue to reign supreme at Roland Garros for a couple more years.

"You see him (Rafael Nadal) train and it scares you," Schwartzman said. "Because of how hard it hits the ball, it bends your racket. He always wants to be better, he will dominate at the French Open for two more years."

Diego Schwartzman defeated Rafael Nadal for the first time in his career at the Rome Masters last year, after nine previous losses. The Argentine won 6-2 7-5 on his way to the final of the tournament, where he bowed out to Novak Djokovic.

"With Roger Federer you are at the mercy of whether he wins or loses the points" - Diego Schwartzman

Roger Federer at the Qatar ExxonMobil Open 2021

During the course of the long interview with ESPN, Diego Schwartzman also let out words of high praise for 20-time Grand Slam champion Roger Federer. The Argentine claimed that you are 'at the mercy' of Federer while playing against him, and that the Swiss can make his opponents look stupid with his bag of tricks.

"With Roger Federer you are at the mercy of whether he wins or loses the points. If Federer is inspired he makes you feel stupid, he doesn't let you do anything," the World No. 9 said. "He has charisma, class, education, goes anywhere and greets everyone."

Roger Federer made his long-awaited return to the tour in Doha earlier this week, following a 13-month absence due to a knee injury. Despite looking rusty, the Swiss maestro picked up a win against Dan Evans in the second round before falling to Nikoloz Basilashvili in the quarterfinal.

Federer subsequently withdrew from the ATP 500 event in Dubai, and will next be seen in action during the clay swing. Serious questions still surround his attempted comeback, but Federer undoubtedly gained important match experience with his exploits in Doha.