Marin Cilic is not that surprised Rafael Nadal lost to Dominic Thiem but does not expect another clay loss to be so straight-forward particularly in the French Open later this month.

Rafael Nadal was dominating the clay-court season since his return from injury last month as he successfully defended his titles in the Monte-Carlo Masters and the Barcelona Open. The Spaniard's dominance was highlighted by his record of 50 consecutive sets won on clay, surpassing John McEnroe's all-time record of 49 on the now-discontinued carpet surface.

However, he crashed out in the quarterfinal stage in Madrid last week in a 7-5, 6-3 loss to Dominic Thiem, notably the only player to defeat Nadal on his favored surface last year as well at the Italian Open.

In the process, Nadal dropped down to No. 2 in the world rankings below Roger Federer and while Cilic finds it surprising that Nadal lost, at the same time, it is not as surprising for the Croatian because it came at the hands of a player regarded as one of the few who could challenge him on clay.

Thiem, though, was not able to use the momentum to go on and win the tournament as he lost in straight sets to Alexander Zverev in the final Sunday.

"When you look at history that he had, you know, that many – or just couple sets that even went to, you know, to extension from 5-all that finished 7-5 or 7-6 in these last 12 months, when you look as that obviously it’s a surprise," Cilic said of Nadal's defeat. "But, on the other hand, I haven’t watched the match but I watched just the highlights and things like that. I felt that Dominic played extremely well. Those conditions suit him for his game. He’s got powerful game. And Madrid allows you to play a bit heavier, a bit faster."

"So I think Dominic played great match and deserved definitely to win. As you know, he beat him, as well, here in Rome last year. So it’s not something as a big surprise that you would say," he said.

Cilic did not play in the Madrid Open due to injury but is expected to feature in the Italian Open this week along with Nadal. The French Open kicks off afterward from May 21 to June 10 and Cilic feels Nadal, who is aiming for an 11th crown, will only be harder to beat on clay there for a number of reasons.

"Rafa feels over there probably the best of all clay court conditions that there are," Cilic added. "The balls are slightly different over there than what we play with on this clay season."

"I think, overall, you know, playing best of five sets against him, also, there on Philippe Chatrier Court, I think the court is really big. And that makes it maybe just vision-wise slightly different than somewhere else," he said. "And I think Rafa’s mentality, in general, on Grand Slams is maybe one percent or slightly better than everywhere else. And I think that makes it just slightly more difficult to beat him there. But, you know, still, we are all great players and we all believe in ourselves. You know, you never know, obviously."