Rafael Nadal has warned those who are tipping him for a 10th French Open title not to write off semi-final opponent Dominic Thiem, saying: "Maybe I won't be up to the challenge."
Thiem caused the upset of the tournament on Wednesday when he knocked defending champion Novak Djokovic out in straight sets to line up a last-four clash with the 'King of Clay'.
Nadal, meanwhile, played just one set of his quarter-final after Pablo Carreno Busta retired hurt at two games down in the second.
The Spaniard is the odds-on favourite to triumph at Roland Garros, but says people should not get ahead of themselves, pointing out that Thiem won their most recent meeting in Rome - Nadal's only defeat on clay in 2017.
"Thiem is a tough player," he said. "I hope that I won't lose. I won in Barcelona and Madrid and I lost to him in Rome. I've played three times with Dominic [this year].
"We can have a look at the statistics. We can talk about statistics for hours, but what is important is to consider the match.
"Either you play well and you advance to the next round, or you lose and you're out.
"If I play well, I hope that I will be able to book my spot in the final. If I don't play well, I will be out of the tournament."
On his status as tournament favourite, Nadal added: "I'd like to thank all those who say that I'm a favourite, but I'm on the court. What matters is to play well.
"So what is being said is positive, but maybe I won't be up to the challenge. We'll see. On D-Day, we'll see if I can set my game up.
"I will make sure that I play my best and produce my best tennis. Beyond all that, as I said at the start of the tournament, everything that is being said and written... of course you have a job to do, but my job is to play tennis.
"I have been on tour for many years and I know that each day there is a different match and there is a different opponent."