Agassi, 47, won eight Grand Slam titles, but retired from playing after the 2006 US Open.
"The rest of my game is working well and there aren't too many ups and downs at the moment", said the 30-year-old Nadal whose record in Paris reads nine titles, 72 match wins and just two defeats. This claycourt season, the German lost first time out at Rome having retired with a back injury after two matches in Madrid.
Still, there are plenty of story lines to keep an eye on at Roland Garros, where play begins Sunday.
However, Federer, at 35, the oldest man in the top five, is skipping the French Open to save himself for an assault on an eighth Wimbledon.
Andy Murray's wretched form ahead of the next week's French Open has left pundits including Boris Becker scratching their heads about what exactly is wrong with the world number one. While a run to the semi finals in Rome, eventually losing to Dominic Thiem was encouraging, back-to-back defeats to Borna Coric and Fabio Fognini were less so.
Those who watched him practice in Italy commented on how quickly Murray was tiring, and with a new illness impacting him just before the French - widely considered the most gruelling of the majors - Murray is approaching the year's second major in far from ideal shape.
Paris - I touched down in Paris today (Thursday) for the French Open and headed straight to Roland Garros as soon as I landed.More news: Novak Djokovic brings in Andre Agassi for French Open coaching role
This year's Roland Garros will be the last for Nadal's coach, his uncle Toni. But I know that Andre is a man who is very, very busy.
Murray, defeated by Djokovic in the 2016 final, has endured a wretched season by his standards with an elbow injury not helping his cause.
"There is no reason for it from my end".
"I think the only player you can really believe will win the French Open is Rafa", Henri Leconte, the last Frenchman to reach the final in 1988, said by telephone.
World No. Thiem showed the blueprint for beating Nadal with a brilliant two-set performance, red-lining throughout a contest that saw him crunch one of his trademark singe-handed backhands at 100mph.
Should the likes of Nadal, Djokovic and Murray falter, then the much-hyped #NextGen, featuring the likes of Zverev and Thiem could profit. He's just 20 and claimed the Rome Masters title with a compelling straight sets win over Djokovic.
But since then, the American has made first round exits in Charleston, Madrid and Rome - where she reached the final a year ago.
"The last few months have been hard but I believe I will turn it around and I hope it starts here in Paris", added the Scot, who has never won the French Open but did reach last year's final where he lost to Djokovic in four sets.