Rafael Nadal
Rafael Nadal has not lost a set on his way to titles in Monte Carlo and Barcelona this season. In this picture, Nadal of Spain celebrates his victory against David Goffin of Belgium in their semi-final match during day six of the Barcelona Open Banc Sabadell in Barcelona, April 28, 2018. Alex Caparros/Getty Images

Toni Nadal, Rafael Nadal’s former coach, has made a surprising revelation suggesting that world number three Alexander Zverev is better than his nephew on hard courts at the moment.

The 57-year-old, who spent almost 27 years as the world number one’s coach before ending the partnership in 2017, believes the 21-year-old German is at his best on hard courts despite winning the Rome Masters which is played on clay.

Nadal senior, who is fondly known as uncle Toni, was in Germany watching Zverev play in the Munich Open where he is the defending champion. He is currently working at the Rafael Nadal Tennis Academy in Mallorca, but revealed earlier he is open to coaching another player.

Uncle Toni had no doubts his nephew is the best on clay, but admitted he could struggle against Zverev on hard courts. Nadal is currently on his way to again dominating the ongoing clay court season having defended his titles at the Monte Carlo Masters and the Barcelona Open.

He has not dropped a set thus far having lost just 21 and 24 games in total on his way to wins in Monaco and Barcelona respectively. The 10-time French Open winner’s former coach named Dominic Thiem as one of the players that can challenge him on clay, with Juan Martin del Potro, Nick Kyrgios and Novak Djokovic the others on the list.

“Zverev is a very good player, he is the world No 3,” Uncle Toni said, as quoted by the Express. “His best surface is, in my eyes, the hard court, because he moves better than he does on clay, even if he won big titles like Rome.”

“Rafa is definitely better (than Zverev) on clay, but Zverev is already a little bit more dangerous on hard. ... Who can beat Nadal on clay? Dominic Thiem as main rival, and other names: David Goffin, Juan Martin del Potro and Nick Kyrgios, but he has elbow issues. Same thing for Novak Djokovic,” he added.

Roger Federer was not on the list of potential challengers as for the second consecutive season the Swiss maestro decided to skip the entire clay court swing of the season including the second Grand Slam of the year at Roland Garros.

Nadal senior was unsure if Nadal misses playing his biggest rival on his preferred surface, but was certain his nephew will be favorite if they come head-to-head. Federer, according to the most successful tennis coach in the history of the game, was saving his energy for the grass court campaign as he was keen to add a ninth Wimbledon title.

“I don't know if Rafa misses Roger for clashes on clay,” Nadal’s former coach said. “But it's clear: Rafa would definitely be the favorite on clay. ... Federer wants to save his energy for the grass-court season, which worked well last year and made him stay injury-free.”