'Novak Djokovic and Rafa Nadal are special - they have something Alcaraz and Sinner don't'

Marin Cilic believes young tennis sensations and "are not yet" at the level of legends and . Despite Sinner and Alcaraz sweeping all four Grand Slams between them in 2024, the Croatian highlighted the two veterans' "mentality" as the difference for the time being.

Cilic is currently competing at the Belgrade Open, having beaten French player Alexander Muller 7-6, 6-2, in his opener. Ahead of that clash, the former World No. 3 was asked about the difference between the 'Big Three': Nadal, Djokovic and Roger Federer, and the younger generation of stars.

The 36-year-old has plenty of experience against the aforementioned tennis aces, having faced all five across his career. And he pinpointed a special trait that Djokovic, 37, and the , 38, possess, stating they are ruthless from the start of matches until the very end and therefore punish opponents who are not "mentally ready".

Cilic told : "I haven't played with Sinner lately, since the 'big three'... Novak and Rafa are similar mentally. If you're not with them from the first ball of the match, you can immediately go home and say goodbye to everyone.

"You have to be mentally ready to play from the first shot because once they get into the rhythm, there's no going back. With Roger, on the other hand, it was very different.

"When I compare them with the young generation, Alcaraz and Sinner have a fantastic level, but they are not yet at that level of mental preparation. The Big Three were at top level from the first to the last second in big tournaments, that's why they dominated tennis for so long."

Spaniard Alcaraz claimed the French Open and Wimbledon this year, defeating Djokovic in the final of the latter, while Italian Sinner swept up the Australian Open and the U.S. Open. The pair have a considerable way to go to reach the 22 Grand Slams won by Nadal and the 24 by Djokovic, who Cilic ranks as the undisputed greatest in the history of the sport.

Answering the inevitable question over who is the greatest ever, the 2014 U.S. Open champion said: "Novak surpassed everyone, Novak is unassailable. I don't know if anyone will ever surpass him. As their rival and acquaintance, they are sport legends, they raised the sport to astronomical levels. We will regret that there will be no rivalry, they raised the whole generation to a new level. What they did was genius."

due to an "ongoing injury". The Serbian will therefore not feature alongside Sinner, Alcaraz, Alexander Zverev, Taylor Fritz and co.