Starting with Federer's 2003 Wimbledon triumph, the Big Three have won 51 of 62 majors. That's a strike rate of just over 82 percent.
Despite showing much promise, the generation immediately following the Big Three, which includes Kei Nishikori, Grigor Dimitrov and Milos Raonic, have yet to win a grand slam title.
But Nadal, 32, believes the new generation of young players is so strong, it won't be long before they will start contending for the sport's biggest prizes.
"For a long time, we have been very consistent," Nadal, a 17-time major winner, told CNN Sport in an exclusive interview at his academy in Manacor, on the Spanish island of Mallorca.
'Not enough good'
Nadal's breakthrough victory came at the 2005 French Open, when he was 19 years old. Since then, no teenager has won any of the sport's four majors in the men's game.
"The previous generation probably, they were not enough good," said the second-ranked Nadal, who won a record-extending 11th Roland Garros title in June.
"But now, yes, in my opinion, we have a new generation that is very good. It is just a question of time, that's my feeling.
"It's just about time that they are going to win grand slams. [Alexander] Zverev, [Dominic] Thiem, [Stefanos] Tsitsipas, [Denis] Shapovalov, [Karen] Khachanov, [Andrey] Rublev, all these guys are good.
"[Nick] Kyrgios, [Alex] De Minaur. All these guys are good, very good. So they are going to be there and they are going to fight for important things for probably the next five, six years."
If they are going to be successful, the next generation will have to get past the Big Three, who between them have won all of the last eight majors. Only Stan Wawrinka (twice) and Andy Murray have interrupted their dominance in the last 16 grand slams.
Nadal said he wasn't surprised at the successful comeback of Djokovic, who won Wimbledon and the US Open after dropping out of the top 20 following a six-month injury break.
"He is too good to not be back," said Nadal about the Serb, who is a 14-time major winner and one of only two players to have beaten the Spaniard on the clay of Roland Garros.
"He did well, he held the passion in the tough moments, and he held the spirit of work when he had some tough moments in the beginning of the season. And then he started, the confidence came back, and Novak is back to his normal level."
Loses comeback match
Nadal began his own comeback Friday at an exhibition event in Abu Dhabi and it ended in a three-set defeat to South African Kevin Anderson, another player knocking on the door of a grand slam breakthrough.
Nadal, who has not played an official match since September after retiring with a knee injury in the semifinals of the US Open, also underwent ankle surgery last month.
The match started well, with the Spaniard taking the opening set, but the big-serving Anderson took the next two to win 4-6 6-3 6-4 to reach the final where he will play Novak Djokovic, who beat the emerging Khachanov in straight sets in the second semifinal.
Nadal later said he would likely not play in the third place playoff match Saturday although he insisted it was a precaution ahead of the Australian Open which starts next month.
"I want to do things step by step. I spent more time on court than I thought," he said.
Murray, a three-time major winner, will also be making a comeback in 2019, starting with next week's ATP event in Brisbane.
"If he is healthy, I am sure he will be back at the highest level," Nadal said about the Scot, a former world No. 1 who has slumped to No. 256 in the rankings following a lengthy spell away following hip surgery in January 2018.
"He is too good, same like Novak," said Nadal.
"But if you have problems, and you have limitations on the movement and this kind of stuff, then it's very difficult to be consistent all the time. I know, because I have a lot experience."