But inevitably, talk of what makes the 'Big Three' of Roger Federer, Rafael Nadal and Novak Djokovic so special came up, with Corretja having encountered the trio, plus having coached Andy Murray.
How a practice match demolition showed Corretja that Kuerten was the real deal - Tennis Legends
"They are thinking like, 'Why can't I be the best in the history?', so that's what I think is giving them this sort of feeling, their passion and the love they have for the game - but also the fact that they can become the greatest, I believe," the Spaniard said on the Tennis Legends vodcast.
They believe that they can be the best in history. They realised that they could be even better than people like Mats Wilander, or Guga Kuerten or Boris Becker or Ivan Lendl.
Kuerten draws heart on court at Roland-Garros in 2001
Corretja recalled he first came across both Federer and Nadal on separate occasions when he was coming to the end of his career.
"When they first started on the tour, you know, I played with Roger several times, and I realised already that he can turn around and just go for it all of a sudden," he said on the vodcast.
"His serve was great, his footwork, but you could see that he was still improving.
"With Rafa, I hit with him one morning at 9am in Barcelona, and he was waiting for me with a sleeveless [shirt] and waiting to hit the first ball.
"I was wearing like a scarf and a hat and everything, like, so cold, and the first ball I threw to him, he went like, boom! He was only 16 years old. So I stopped and I said, 'How can you hit the first ball so hard?'
He said, 'I'm playing 100% full speed from the first ball till the last ball', and I was like, 'Oh, this guy is something special!'
Look out for the full Tennis Legends vodcast and the latest podcast on Thursday, and make sure you stay tuned to Eurosport for much more from numerous tennis stars...