Dominic Thiem and Alexander Zverev have both troubled him on clay, but the world No 1 remains the strong favourite heading into Roland Garros
Rafael Nadal may have wobbled in Rome but is still the man to beat at the French Open
When the clay-court season began last month in Monte Carlo it was with Rafael Nadal's name at the top of the world rankings.
Fast forward to Sunday and the conclusion of the Rome Masters, the final ATP tournament before the French Open begins on May 28, and the Spaniard's name is still there, 100 points clear of Roger Federer.
But that does not tell the full story of the 31-year-old Spaniard's clay season. It has been another dominant season in many respects with titles won at three (Monte Carlo, Barcelona and Rome) of the four competitions held.
Despite that dominance, his leading rivals can sense of a glimmer of hope that Nadal's usual routine of winning at a canter at Roland Garros is a foregone conclusion.
Victory in Rome actually gave Nadal the No 1 ranking back after he had lost it to Federer, who is sitting out the clay season, after it was surrendered following a surprise defeat in straight sets to Dominic Thiem in the quarter-finals in Madrid. Given Nadal had gone 12 matches on clay without dropping a set, the loss to Thiem was a reminder that Nadal is still mortal on clay.
Rome was mission accomplished in the respect that Nadal bounced back to winning ways, regaining the No 1 ranking in the process, at the first opportunity.
In winning the title for an eighth time and first since 2013, Nadal offered a chink of light, albeit a small one, to his rivals. He dropped the first set of his quarter-final with Fabio Fognini in Rome, and then was pushed hard in the first set of Saturday's semi-final against Novak Djokovic. But it was in his three-set win in Sunday's final against Alexander Zverev that the real wobble came about.
Having been broken in the first game of the match, Nadal had looked as if he was in for a comfortable afternoon's work as he won the next six games on the spin to take the set 6-1. Sensing he had nothing to lose, Zverev went for it and starting going after Nadal's serve, swinging big and was rewarded as he won the set 6-1 and then broke early in the third set.
No-one will ever know what would have happened if the game had gone on uninterrupted but two short rain breaks undoubtedly gave Nadal time to gather his thoughts and break up Zverev's momentum.
Nadal would go on to triumph but Zverev can take heart from the fact he had his more experienced opponent on the ropes. That is something not many can claim to have done against the King of Clay.
Certainly Zverev and Thiem can be hopeful that if they do end up facing Nadal at Roland Garros they can cause him problems, although whether that is enough to win three sets off him is questionable.
Nadal's efforts in Rome were both concerning and admirable. He was not at his best and looked jaded, lacked ruthlessness on occasions, most notably in allowing Djokovic to take the first set of their semi-final to a tie-break after he had been a break up. But when up against it against a younger opponent he found an answer and showed that even after all the titles and success he has he still has the desire to be the best.
Nadal has only lost two matches in his entire career at Roland Garros, and you suspect the only thing standing in his way of an 11th title is his own body and whether it can handle the rigours of the two-week tournament.
Thiem beat Nadal in Rome 12 months ago, but was then trounced in the semi-finals in Paris, winning just seven games. Zverev has yet to make it beyond the last 16 of a grand slam and was beaten in the first round 12 months ago by Fernando Verdasco.
Defeat in Madrid and a scare in Rome has given Nadal a reality check that if he is not at his best there are players who can challenge him on clay.
It is unlikely to go unheeded and although it may not be the most convincing preparation for his favourite grand slam, it is hard not to see Nadal winning a 17th grand slam on June 10.