Rafael Nadal believes his performances on clay this year are "normal" as his incredible dominance on the surface shows signs of diminishing.

For the third time in as many tournaments on clay this year, the Spanish star bowed out in the semi-finals, losing to Stefanos Tsitsipas at the Madrid Open on Saturday.

Nadal, 32, has won a record 11 French Open titles – those successes coming in just 14 years – and will again head to Roland Garros as one of the favourites.

Speaking after his 6-4 2-6 6-3 loss to Tsitsipas, he said his run on clay this year was closer to what would be considered "normal".

"I think that it's more normal what is happening right now, than what happened in the past 14 years," he said, via the ATP Tour.

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"I think I have tennis ahead of me. I have time ahead of me. I'll be able to try to win this kind of tournament that I was not able to win this year. And what I have to do is to be fit and to play properly and a high tennis level.

"If I manage to do that next year, I think I will still have a very good opportunity to fight for all of these titles and for the rest of the year, I still have two [clay-court] tournaments. And we will see what happens there."

Tsitsipas' victory sent the 20-year-old Greek into a final clash against world number one Novak Djokovic.

The world number nine was delighted with his win, his first in four meetings with Nadal.

"I'm really happy that I proved myself and played one of my best games this year. I'm really happy that I'm fighting," Tsitsipas said.

"I'm in the zone, I'm enjoying tennis at its fullest potential. It's really nice to be able to play this way.

"Today's victory is an unbelievable feeling. I cannot explain it any further."