A host of youngsters are taking the tennis world by storm but Federer, now 36, remains on top of the game.
The Swiss beat Hyeon Chung, 21, in Indian Wells this week and he plays Borna Coric, 21, in the semis on Saturday night.
And ahead of the clash he admitted he knows that it won’t last forever due to the next generation coming through.
He said: “The boys are learning and getting better and better. Eventually they will drive us out – and that will be our end. It’s pretty simple.
“But experience is a good thing. It’s not just about having young legs.
“You have to play the ball to the right place, then the other one will run more – and maybe get tired faster.”
Federer stormed his way into his 11th semi-final at the tournament with a 7-5 6-1 win over Chung.
The Swiss will go head-to-head in the final four with Coric, who beat South Africa’s Kevin Anderson 2-6 6-4 7-6 (7/3).
Juan Martin del Potro has reached his third semi-final at Indian Wells with a victory over Philipp Kohlschreiber.
The No 6 seed toppled his German opponent 3-6 6-3 6-4 after two hours and seven minutes on court at the BNP Paribas Open.
Kohlschreiber got off to a dominant start, winning two break points in the first set, and looked to be on course to repeat his previous victory against the Argentinian at the Stuttgart Open in 2016.
But a determined del Potro improved on his serve in the second set, winning 82% of points on his first serve, and broke his opponent to serve for the set at 5-3 and force a decider.
Del Potro’s form continued into the third as he claimed the first break and saw out the set 6-4, crushing Kohlschreiber’s hopes of reaching his first Masters 1000 semi-final in 83 appearances.
Speaking on court after the match, del Potro said of his opponent: “He’s a very smart guy, his game is so good, he made me run a lot, so my legs are completely tired.
“But at the end of the match, I played well, and in the important moments. I am so happy to be in the semi-final.”
Del Potro will next face Milos Raonic at Indian Wells after the Canadian defeated Sam Querrey 7-5 2-6 6-3.