Ruud has never before competed against any of the best three players in the world – Federer, Nadal and Novak Djokovic.
But he takes on Swiss star Federer in the French Open third round tomorrow.
However, the 20-year-old Norwegian admitted he always supported Nadal when he was growing up.
“To be honest, I’ve been a little bit more of a Rafa fan and Rafa guy,” Ruud said.
“But those two have always been my two absolute favourites.
“And, you know, I have just an amazing amount of respect for him and everything he’s done for the sport, how gentle he is on and off the court and he’s just a perfect example for all young players.
“Of course I remember some incredible matches between him and Rafa, you know, in my very young days.
“I remember especially the Wimbledon final where Rafa ended up winning in that amazing fifth set.
“And I remember Roger beating I think it was [Andy] Roddick that year after in another amazing five-setter.”
Christian Ruud, father to Casper, competed at the French Open in 1999 when Federer made his debut at Roland Garros.
“Well, I mean, my father retired when he was pretty young,” Casper Rudd added.
“He [my dad] was around 30 years old. So, you know, Roger was just coming up, I think, a little bit.
“He was around 18, 19 I think when my father kind of stopped.
“So I think they practiced together once, he told me, but never played him.
“I will be the first Ruud to say that I was able to play him, so that bit’s funny.
“But ever since I can remember I’ve been watching Roger on TV. So of course he has had an amazing career and the most winning player ever.”