The two will play in the semifinals for the first time since their legendary five-set encounter in the 2008 final that gave Nadal his first title at Wimbledon.
They are still at the top of the game, having added and adjusted the way they play to keep winning and prolong their careers. Federer has returned to a more attacking game, improved his backhand drive, and added a few strategic elements. Nadal has developed his offensive game and introduced more variety in his play and court positioning.
Both have also reduced their schedule to reduce wear and tear, and come back from injuries to win again.
According to Nadal, the changes are what has been required to keep them competitive.
"I am running less so I need to serve better," he said. "I probably cannot play 20 weeks per year any more, so I need to reschedule my planning to improve things to be very competitive every single time that I am on court.
"Of course, I am serving better. Of course, I am hitting the backhand better. Maybe volleying better, slicing better. But even like this, I don't know if my level today will beat my level of years ago."
Federer agreed with Nadal's assessment, saying, "Improved so much over the years on this surface. He's playing also very different than he used to. Haven't played each other in a long, long time on this surface. He's serving way different. I remember back in the day how he used to serve, and now how much bigger he's serving, how he finishes points."
Similarly, he told press from Switzerland his own game has changed during his 20 Grand-Slam winning career. "Generally, I think I have a higher percentage of offense," he said. "I think I have a better rhythm in my shots.
"I can play more with slice and find other ways to open up the court."
He is also happy with the way he's been playing during the tournament through the quarterfinals. "I feel good on the court. Even down a set or a break," he said to press. "I have the 1-2 punch under control. My serving is good. I'm in phases in returning."
Nadal also says he is satisfied. "I think I am playing with a very high intensity, playing aggressive, serving well, and returning."
Something that hasn't changed, though, is their passion for the game. That's why they're still at such a high level, says Nadal.
"In terms of readapt my game, readapt our game, talking about me and Roger, for sure there is lot of things that we find a way to keep being one of the best of the world," he said. "The only thing and probably the only reason, why we're able to be where we are, is because we love the game and we have big respect for this sport."
It will be their 40th career meeting.