That is the opinion of Sky Sports tennis pundit and former British No 1 Annabel Croft.
Croft and Greg Rusedski were speaking ahead of Federer’s second game of the ATP World Tour Finals in London against Alexander Zverev tonight.
The Swiss legend won his opening game against Jack Sock on Sunday, with World No 1 Nadal playing his only game on Monday, a defeat to David Goffin, before withdrawing with a knee injury.
Federer’s clash with Sock drew a 17,800 capacity crowd as he dispatched the Ameircan in straight sets, but there were large areas of unoccupied seating as Nadal took on Goffin.
Former US Open finalist Rusedski says Federer is the player the spectators want to watch.
“This is what everybody wants to see,” the Brit said.
“It doesn’t matter if the Swiss fans have booked it out, everybody in the world, not only the Swiss, want to see this man.
“When he plays at Wimbledon, whether it’s (Andy) Murray, whether it’s Nadal, the crowd are usually always behind Roger.
“He’s a once in a century player that we get to see.”
Croft agreed with Rusedski’s claim and says it was clear Roger Federer had the loudest reception of the week so far.
“It’s hard to disagree with you there Greg, he really is,” Croft said.
“That was the biggest cheer we have had by a mile. The cameras and the phones that were going off around the arena just to catch a picture of him.
“He loves it doesn’t he, he is like a rock star who never wants to get off this stage.”