Nadal will be playing in his 14th Roland Garros final on Sunday and 30th overall at the Grand Slams.
Victory will deliver a record-extending 22nd major and 14th French Open, 17 years after his title winning debut in Paris.
The 36-year-od Nadal is, however, as surprised as anyone to have got this far.
A chronic left foot injury which has plagued him throughout his career flared up again in Rome last month, putting a serious question mark over even making it to the French capital.
"Without a doubt, I'd prefer to lose the final and have a new foot," admitted Nadal who has not hidden the brutal reality that every match he plays at Roland Garros may be his last.
Despite his fears, Nadal has impressively battled his way into Sunday's championship match.
He needed five sets and more than four hours to see off Felix Auger-Aliassime in the last 16 and another four hours to get past Novak Djokovic in the quarter-finals.
Alexander Zverev then pushed him all the way for three hours in the semi-finals until a sickening ankle injury forced the German world number three to quit on crutches.
Despite the German's bold all-or-nothing challenge, Nadal still cut an impressive presence on court, at one point coming out on top in a lung-busting 44-shot rally.
His record at the French Open now stands at 111 wins and just three losses. Djokovic was responsible for two of those defeats.
Nadal was only 19 when he won his first French Open in 2005.
- 'The greatest' -
Victory on Sunday will make him the tournament's oldest champion, eclipsing 34-year-old compatriot Andres Gimeno who took the title 50 years ago.
World number eight Ruud, 23, is the tour's in-form clay court player.
Not only have seven of his eight career titles come on clay, but he has won 66 matches on the surface since 2020 and played in nine finals.
Ruud is the first Norwegian to reach a Grand Slam final.
Robin Soderling, a fellow Scandinavian, is the only other man apart from Djokovic to have defeated Nadal in Paris back in 2009.
Ruud has been training at Nadal's academy in Manacor since 2018 alongside his father Christian, a former top 40 player, and Spaniard Pedro Clar.
Nadal and Ruud have never met professionally but they are often hitting partners in Spain where the Norwegian admits "he has beaten me pretty much all the times in practice".
"Casper has a very good character to play tennis. He's very relaxed, humble. He's always in a positive mood about learning," said Nadal.
"I think in the academy we were able to help him a little bit during this period of time."
Ruud was just six years old when Nadal was first crowned French Open champion and describes the Spaniard as his "idol".
"I could probably tell you all the finals and who he has played and who he has beaten, because I watched them all on TV," said the Norwegian.
"He's the greatest clay court player of all time and one of the greatest all-around players."
Victory for Nadal will give him the Australian Open-French Open double in the same year for the first time.
That would also put him halfway to a calendar Grand Slam, achieved only three times in history, the last of which was by Rod Laver in 1969.
"I fought, I have done all the things possible to give myself another chance to play in the final of Roland Garros," said Nadal.
"All the sacrifices and all the things that I need to go through to try to keep playing, really makes sense when you enjoy moments like I'm enjoying in this tournament."
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