He is currently competing at the ATP World Tour Finals and is yet to lose a game against his younger opponents.
"I will try to do my best to play a better match than in Basel, for sure", added Goffin, who describes the indoor hardcourt conditions at the O2 Arena as "perfect" for Federer. You can take the ball earlier. "That's the reason he's in the final".
"I've never found a key to beat Roger", Goffin said. Luthi also spoke about one of the four Federer's losses, in Dubai to Evgeny Donskoy, in which Federer had match points. He was true to his word. There is no wind.
Federer breezed past Marin Cilic in his final match of the round-robin stage with a three-set win. Dimitrov is the first Bulgarian.
It is hard to repel the worrying feeling, meanwhile, that tennis is leaving Andy Murray behind. Goffin used the time between sets to come up with a new approach and promptly grabbed a break of serve to start the second set, playing much more aggressive tennis.
The 2016 champion has much to ponder: a hip that is healing only slowly and a future without Ivan Lendl, who late on Friday left him for a second time. Nobody saw that one coming. "It was such a special moment", said Goffin.
GETTYDavid Goffin has yet to taste success over Roger Federer
"You've always got to expect a slow process", he said. "I had the best time of my life this year, so can't wait to go back there". Maybe I helped him doing it, maybe not.
A lot of people would.
Federer has had a stunning 2017, winning seven tournaments, including two Grand Slam titles.
But one snapshot of beauty of the Swiss legend will leave fans dizzy at the sight of his talent. When he had them, he was very committed.
The 26-year-old will be full of confidence after taking out world No. 1 Nadal, although this surface is statistically his worst. "It was my day". The set scores were 2-6, 6-3, 6-4.
Goffin, in no mood to roll over, broke for 3-0 and held for 4-1. Federer briefly rediscovered his fluency but could not stop Goffin serving out to love to level at a set apiece.