The eight-time Grand Slam champion currently coaches the pair’s regular foe Novak Djokovic, with the Serb boasting winning records against both players.
Federer leads the all-time Grand Slam charts, with a men’s record of 19 majors – ahead of Nadal’s 16 – and is widely labelled as the GOAT for his remarkable achievements.
But Agassi believes that Nadal’s one-sided head-to-head (23-15) damages Federer’s claim to be crowned as the greatest in history.
‘A player can not be considered the best of all time if he has been beaten so many times by a rival,’ the American told French outlet Le Matin.
Most Grand Slam titles
19 – Federer
16 – Nadal
14 – Sampras
12 – Djokovic
12 – Emerson
However, while he thinks Nadal’s record over Federer would give him the advantage to be crowned as the GOAT, he pointed out that all these distinctions are arbitrary.
‘My choice is purely arbitrary,’ he added. ‘I could just as easily defend the opposite view and prove to you that Federer is the best.
‘The debate has no rational basis, it comes down to ‘and if …’. It’s just a debate.’
Federer, Nadal and Djokovic h2h
Federer 15-23 Nadal
Federer 22-23 Djokovic
Nadal 24-26 Djokovic
Although he championed Nadal, Agassi was quick to praise the 36-year-old Swiss for his outstanding career.
‘Federer is unique. In all: greatness, accuracy, ease. He plays tennis so differently from others.
‘Federer gives off that feeling of control, of having a solution for every problem.
‘We cannot deny that Federer will mark the sport forever.’