Rafael Nadal targets a ninth French Open title with his lethal clay court game and enduring confidence facing their biggest crisis in a decade.
The Spaniard, whose stirring comeback from a seventh-month injury lay-off was one of 2013's headline acts, boasts a formidable record of eight titles, 59 wins and just one defeat on Roland Garros's famed crushed red brick.
But the cracks are beginning to show.
With his 28th birthday just around the corner, the world number one has spent the spring strangely disorientated on the same European clay courts where he once conducted business with a deadly if humble precision.
His defeat to world number two Novak Djokovic -- the man many expect to dethrone him as king of Paris on June 8 -- in Sunday's Rome Masters final marked the first time since 2004 that he had lost three claycourt matches in the same year.
Nadal, a seven-time Rome champion, was taken to three sets in four of his five matches in the Italian capital.
He successfully defended his Madrid Masters title but only after Kei Nishikori, having won the first set of the final, was forced to retire with a back injury.
Before that, Nadal was knocked out in the quarter-finals in Barcelona by compatriot Nicolas Almagro and exited the Monte Carlo Masters also at the last-eight stage at the hands of David Ferrer.
At both those events, Nadal was an eight-time champion.
But Nadal is not reaching for the panic button just yet. He still boasts a 13-4 claycourt record over Djokovic, including victory in the 2012 Roland Garros final and in the 2013 semi-finals where he had trailed 4-2 in the fifth set.
"Two weeks ago, my chances to play well in Roland Garros were not very high. But I will arrive now more encouraged," insisted Nadal, who will nevertheless go to Paris with just one European claycourt title for the first time in 10 years.
Djokovic is the man in ascendancy. The right wrist injury which forced him to miss Madrid was forgotten in his fightback from a set down to beat Nadal in Rome.
The Serb fired an incredible 46 winners to the Spaniard's 15 -- an almost unheard of brutality on a slow claycourt with Djokovic keeping Nadal on the backfoot with his willingness to come to the net and confidence in his ability to hit forehand winners.
Djokovic, who still needs a French Open title to complete a career Grand Slam, has now beaten Nadal in their last four meetings.
He has also captured five of the last seven Masters and could reclaim the world top ranking by the end of Roland Garros.
"I played with no pain and increased the level of tennis as the week in Rome went on," said Djokovic, who turns 27 on Thursday.
"Winning against Rafa in the final of a big tournament on clay, his preferred surface, is definitely a confidence booster. Experience helped me stay calm and play the right shots at the right time."
- Federer, Wawrinka threats -
Nadal and Djokovic's biggest threats are likely to come from Roger Federer, the 2009 champion, and his rejuvenated Swiss compatriot Stanislas Wawrinka, this year's shock Australian Open winner.
Federer, who will be 33 in August, could be forgiven for being distracted.
He lost his first round clash in Rome, having only made a late decision to play following the birth of his and wife Mirka's second set of twins on May 6.
The 17-time major winner hopes to have all of his four children -- newly-arrived Lenny and Leo and Myla and Charlene, who were born in 2009 -- in Paris.
The world number four Swiss will be playing Roland Garros for the 16th time, but his last two visits have ended in defeats in the semi-finals and quarter-finals.
World number three Wawrinka added the Monte Carlo Masters title to his Australian Open trophy by beating Federer but then suffered early defeats in Madrid and Rome.
The 29-year-old's best French Open was last year where he made the quarter-finals, losing to Nadal in straight sets.
Elsewhere, Andy Murray, whose decision to skip the French Open in 2013 paid handsome dividends in the shape of the Wimbledon title, was a semi-finalist in 2011.
But the Briton has never won a claycourt title. That suggests veteran David Ferrer, the runner-up to Nadal last year, and new generation stars such as Rome semi-finalists Milos Raonic and Grigor Dimitrov as well as Barcelona champion Nishikori are most likely to be tournament dangermen.