Former ATP star Gilles Muller believes Roger Federer is 'above Rafael Nadal and Novak Djokovic' in the discussion about who is the greatest of all time.
The 'big three' have been battling it out for more than a decade now to attempt to settle the debate of which of them will be the GOAT.
Nadal has won the most majors, Djokovic has most of the numbers on his side, but Muller has made the case for Roger Federer, saying he 'took tennis to a higher level.'
"If we look at the numbers and the Grand Slams, now it's Rafa," Muller said. "To be completely honest, for me Roger Federer is above all.
"I think that he raised tennis to a higher level, made it more popular, the prize funds are now this big largely because of him.
"I think the way he played was also spectacular, the most beautiful of all - he made every shot look easy, it was special to watch him," said Muller.
Muller played Novak Djokovic four times and lost all of them, and he is certainly a fan of the Serbian.
However, his decision ultimately appears to be based on a belief that numbers alone cannot, and should not, settle the debate.
"Novak is also a spectacular tennis player and I think he will end up with the most Grand Slam titles, unless something unexpected happens - if everything goes well physically, he will play for a few more years," Muller said.
"It would be easiest to look at the numbers, but when we take everything into account, I would put Roger above Rafa and Novak."
Gilles Muller played the big three 15 times in his career, losing 13 of them. His only two wins came against Rafael Nadal.
For more exclusive content from Tennisbuzz, including news, features, trivia, promotions and more, please be sure to sign up for our newsletter below or via our home page.
Why not test your tennis knowledge by tackling one of our fiendish quizzes too?