What has become a major talking point in recent months is the lack of real challengers from the current youngsters to the traditional Big Four in tennis, who have won an impressive combined 50 Grand Slam titles.
Djokovic and Murray dominated 2016 while the recently concluded 2017 season has been all about the career resurgences of Nadal and Federer, who have split the four Grand Slams between themselves and won a combined 13 titles.
Uncle Toni praised the foursome along with David Ferrer for being consistently good compared to their previous generation.
"Rafael Nadal, Andy Murray, Roger Federer and Novak Djokovic and someone else, like David Ferrer, have been very focused with a very big ability of [being able to] sacrifice," Toni told El Mundo via Tennis World USA.
"For Federer, despite his age and all that he's won, tennis continues to be a priority. The same can be said for Rafa, despite all his injuries. There have always been very good players, but this [current] generation may have been more committed.
"Nadal, Federer and Djokovic won 47 Grand Slam titles combined. If we take as example Jimmy Connors, Bjorn Borg and John McEnroe's generation, (though) it was very brilliant as well, we see they only won 26. The [current] generation that was supposed to take over wasn't good enough."
While certain young players have impressed this year such as Alexander Zverev, who notably won five titles in 2017, the next generation have as a whole, underperformed, particularly in the Grand Slams.
It has begged the question for tennis fans on whether the youngsters can win a Grand Slam until the Big Four have retired, especially when one considers that the likes of Nadal, Federer and Djokovic all won their first major titles at very young ages.
However, Uncle Toni believes the reason the next generation have not taken over is because of today's society. He believes youngsters these days are over protected that results in less development.
"That's the reflection of society we live in, which is ultra protective with kids," he explained. "When we came to the Tour, the best players were aged 21-23.
"Now, at this age most of them on the Tour have't come of age. yet. Why? Because kids are more immature and they struggle to develop."