For well over a decade, the now World No.2 Roger Federer, has played and beaten the very best to ever grace a court, engaging in some of the most competitive rivalries in sport's history.
Although, still well on top of his game, Federer believes there are a few younger players who have the talent to bring out the best in him and create even bigger rivalries.
One name in particular that always turns heads, is that of Nick Kyrgios, one of the most disputed talents in the game.
Kyrgios is an athlete who has the ability to frustrate both opponents and fans, with his beauty on the court marred by his immaturity and, at points, lack of desire to succeed in tennis.
The 36-year-old Federer has hailed the young Australian as someone he could realistically see himself being rivalled with in the years to come, especially if there is more game time between the two.
"I think there is still an edge to it, but the younger players still need more time to break through, and we haven't played the amount of times I was playing against Andy and Novak in 2007 and 2008, I do think we still need more time to play more often for some rivalry to build," Federer stated.
Federer and Kyrigos most recently duelled terrifically in the Miami Open in April of this year, with Federer securing the win to make it one win a man after Kyrigos' stunning Madrid victory back in 2015.
"If you look at the Kyrgios match in Madrid (in 2015) and Miami (in March), it was edgy."
The Swiss megastar understands and appreciates to a degree what the controversial Australian is about, and added that the intensity and contrast between the two stars made for a breathtaking encounter.
"We had six tie-breakers. Clearly in the tie-breakers you are not just pulling the sunchair out, it is serious stuff. Nick was smashing rackets, I was trying to keep it together. It was a great atmosphere."
With Federer's endorsement, hopefully Kyrgios can push on and reach the heights his potential will most definitely let him. One route to this may have to be through beating the Swiss 36-year-old in the Laver Cup, for which they are on opposing sides and the arena in which Kyrgios has just beaten Nadal and Berdych.