Dominic Thiem and Rafael Nadal
Dominic Thiem was the only player to beat Rafael Nadal on clay in 2017 but could not repeat his win in Monte Carlo. Pictured, Nadal of Spain (right) and Thiem of Austria (left) shake hands after their singles match during day six of ATP Masters Series: Monte Carlo Rolex Masters at Monte-Carlo Sporting Club in Monte-Carlo, Monaco, April 20, 2018. Julian Finney/Getty Images

World No. 7 Dominic Thiem says beating Rafael Nadal on clay is one of the most difficult things to do but believes it is more likely to happen in the Madrid Open and Rome Masters.

Nadal returned to action for the first time since the Australian Open at the Monte-Carlo Masters as he went on to win his first title of the year. He followed it up by retaining the Barcelona Open last month in what was his 55th clay title and his 77th overall title.

The Spaniard's dominance on clay looks set to continue in the Madrid Open this week as he will look to not only retain another title in his bid to remain atop the rankings but also extend his own record of 46 consecutive sets won on clay — an all-time record on any currently played surface.

However, Thiem believes if Nadal will suffer defeat anywhere on clay, it is either in Madrid or Rome because of the speed of the court as well as the high bounce, though he admits whoever will emerge victorious against the 16-time Grand Slam winner must be at their absolute best.

"It's one of the most difficult things in the sport to do that but on a good day for some players, I think it's possible," Thiem said, as quoted on Tennis World USA. "Especially here in Madrid and in Rome. I think the chances are the highest. ... Out of all the clay-court tournaments, I think here and in Rome, it's the most difficult for him. Of course, he's still playing amazing also in these tournaments but for the other players, it's getting a little bit easier because it’s faster and there's a higher bounce."

"The chances are slightly better, I would say, than in Monte-Carlo, For example, I would say because it’s just faster and a little bit higher bounce and it’s a bunch of players who have chances. Of course, he's the top favourite. If everything goes normal, he's going to win the tournament I would say."

Thiem, hailed as one of the few who could defeat Nadal on the surface, was notably the only player to beat him on clay in 2017 after winning in straight sets during their Rome Masters quarterfinal clash last year.

However, the Austrian would later lose against the 31-year-old at the French Open and most recently lost to Nadal in the Monte-Carlo Masters last month where he only won a total of two games.

If he is to face Nadal in Madrid, Thiem says he will try and overwhelm him otherwise he risks getting the same treatment.

"It's from the first moment on, he doesn’t give you any air to breathe so if you want to beat him or if you want to compete well with him, you have to do the same," Thiem added. "You have to be on fire from the first moment on. Or if you don't do that, it happens like what happened to me in Monte-Carlo – he just kills you, you know? But chances are there if you're playing at a high level from the first moment on."

Thiem will face Federico Delbonis in his round of 32 match while Nadal will begin his title defense against Gael Monfils on Wednesday.