In the last 15 years, he has lost just twice: once to an inspired Robin Soderling, who played the tournament of his career in 2009, and then to Novak Djokovic as well as withdrawing injured at the third-round stage in 2016.
But one away from Roger Federer’s record of 20 Grand Slams, the 34-year-old has rarely arrived on the Roland Garros clay looking more fallible.
For one, he has just three matches under his belt in the past six months, plus there is the calendar shift to the current end-of-September start.
What that means is the courts are wetter and more slippery, in theory not giving Nadal as much as a spin advantage as normal and thereby closing the gap between him and the rest of the field. At the preceding Italian Open, it showed, Nadal broken five times and producing 30 unforced errors as he suffered an early exit.
But realistically there are still probably only two men that can challenge him for the title, both of whom arrived in Paris heavily defined by the events of the last Grand Slam.
US Open champion Dominic Thiem will be bidding for a hat-trick of finals in Paris while Novak Djokovic, disqualified in New York for striking a line judge, comes with a point to prove after he let Grand Slam No18 slip away earlier this month, or at least be delayed in its attainment.
Three-time French Open champion Mats Wilander said: “I think the field has a much better chance this year than any year I can remember since Rafa started winning.
“I think it’s Novak, Rafa and Dominic who are the three favourites. I would put Novak slightly ahead of the other two. But this is perfect conditions for Thiem. He can hit through a heavy clay court. I think he’s going to be extremely dangerous.”
There are, though, question marks about Thiem too. Having picked up a maiden Grand Slam title after three times as a losing finalist, it is a moot point whether psychologically more than physically he can recover to be at his best in Paris.
Thiem, however, believes the New York win will prove to his advantage. He said: “Now that I have won a Grand Slam final, I can finally tick off one of the biggest aspirations of my career. I am now fully focused on my clay game and the French Open.”
The last man to win a Grand Slam prior to Thiem outside the big three, Stan Wawrinka, remains an outlier in the men’s draw if he can regain his best form.
He faces a potential first-round match for the ages against Andy Murray, a repeat of their epic French Open semi-final in 2017 which eventually ended with Wawrinka needing double knee surgery and Murray having a metal hip inserted.
As ever, brittle knees remain a concern for Nadal, a factor along with Covid in his decision to stay away from the US Open with two Grand Slams so close together.
And yet he remains the favourite, albeit with a sense to Djokovic, Thiem and the rest of the field that the cloak of invincibility is slipping.