That’s the view of former Wimbledon winner Pat Cash as the pair prepare for this year’s tournament at SW19.
Between them, Roger Federer and Nadal have 37 Grand Slam titles, with the Swiss star leading the race with 20.
Eight of his major titles have come at Wimbledon with Nadal winning just twice in south-west London.
Despite their age, Federer is 36 and Nadal 32, they are both among the favourites to win Wimbledon this time around.
And Cash believes both Federer and Nadal’s prolonged success is all down to their ego.
“I don’t understand how he [Nadal] does it, I really don’t know,” Cash told CNN. “It’s some form of obsession, there is no doubt about it, I don’t know what drives him, but it has to be.
“Federer as well … Why would he be playing at the age of 36 other than to please your adoring fans, and because he likes playing and he likes to win titles?
“There is some obsession, there is some ego-driven thing that’s really pushing them massively.
“Novak [Djokovic] is normal. Novak said, ‘I lost motivation’. That is normal.
“In my era, the Tour wasn’t as nice and as comfortable as it is now. We had to travel and go overseas and it wasn’t exactly first-class seats. We almost all lost motivation.
“[Bjorn] Borg retired at 26, I lost interest at 24 or 25, [John] McEnroe has talked about it, [Andre] Agassi has talked about it. That’s normal.
“What’s not normal is Federer and Nadal. And I don’t know what it is. Maybe to get better, maybe to win more.
“Whatever it happens to be, it’s phenomenal. To me, it is kind of weird and most guys, the ex-players, they sort of look at them and go ‘Why is Federer still playing?’
“Nadal, I think he feels like he’s got something to prove, he’s had a few years off, he’s come back and he’s had some motivation to get back again after injuries.”
Rafael Nadal faces Dudi Sela in the first round at Wimbledon while defending champion Federer meets Dusan Lajovic.