Ivan Ljubicic admits Novak Djokovic was his “toughest” opponent to face but believes Roger Federer and Rafael Nadal had more of an impact on tennis. The former coach was quick to shrug off the question of who the greatest was in the sport, making arguments for all three to be crowned the top dog.

He said: “When Novak was on, it was maybe the most difficult for me, because me having a big serve and relying [on] a lot of free points with my serve… I mean with him, it was just not possible.”

Highlighting Federer’s unpredictable nature, Ljubicic added: “Against Roger, was complicated, because he would always do something different. I remember I played him like four times in three months in the beginning of 2005. It was always a different match. I thought after losing to him, Okay, now I know what I need to do.”

In terms of Nadal, he said: “I felt against Rafa, you have time. He stays far back on the return, so he kind of lets you do your thing, especially on my service games. So I felt rather comfortable.

“Obviously, I lost a lot more times than I won, but I did beat him twice. I always felt like if I played well, I’m going to have a shot, I’m going to have my chances. And also he doesn’t serve big, so you’re always in the rallies. And of course it’s really difficult, but I never felt like it’s impossible.”

When asked who the GOAT out of the three was, Ljubicic snubbed Djokovic and praised the other two’s “impact” on tennis. He said: “They are different. It’s really difficult to say who is better. Obviously Novak won the most, it’s clear.

“But for me, the impact that Roger had on the game, and Rafa, in different moments – it’s huge. Maybe bigger than Novak.

“But… what is the GOAT? If we go by the results, obviously Novak is the one who won the most. But the impact on the game I feel like Roger definitely had, at least for me, was tremendous and still is.”