The Spaniard, written off as a contender in Paris after a quarter-final loss to Novak Djokovic in 2015 and an injury-enforced pull-out before the third round a year ago, arrives at Roland Garros as the overwhelming favourite.
The Spaniard, who hits 31 next week, has turned back the clock to sweep through the European claycourt season with titles in Monte Carlo, Barcelona and Madrid and is a daunting obstacle for anyone with genuine title ambitions.
However, Federer, 35, has confirmed he will skip the French Open in order to get himself prepared for Wimbledon.
Djokovic, seeded second, has been slumping this year a bit and has hired former French Open champion Andre Agassi to coach him in Paris.
"I had a lot of success on clay, winning three events out of four that I played", Nadal said when asked about his fitness.
Record nine-time victor Rafael Nadal and title-holder Novak Djokovic set off Monday ahead of a French Open collison course, while champions past and present meet in the women s first round.
Novak Djokovic revealed that a chance telephone call sparked his decision to hire U.S. legend Andre Agassi as his new coach.
World No. 1 Angelique Kerber has endured a miserable clay-court season, losing early in Stuttgart and crashing out in her Rome opener, while retiring from her last-16 clash in Madrid with a lower back injury.
Djokovic's relationship with the 47-year-old Agassi, an eight-time major victor, is limited, for the moment, to just the French Open. "It was my best year, but. when I played tournaments on clay, I was not playing so well".
Play begins on Sunday at Roland Garros. Heading into the French Open, the men at Nos. "A new inspiration, someone who knows what I'm going through", Djokovic said Friday, two days before the start of the French Open.
"I will think he will try everything to win Le Decima, I think it will be very unique in tennis to win a Grand Slam title 10 times".
World number one and top seed Andy Murray will be up against Russian outsider Andrey Kuznetsov and is in the same half of the draw as 2015 champion Stan Wawrinka, who will come up against a qualifier in the first round. The men's draw will see a full slate of players in action with the exception of Roger Federer who has missed the whole clay season. "It felt like we know each other for a very long time".
When Djokovic completed the career Grand Slam by winning his first Roland Garros title in 2016, the Serb held all four majors at the same time.
Canadian fifth seed Milos Raonic raced into round two with a routine 6-3, 6-4, 6-2 victory over Steve Darcis of Belgium.