This year’s Roland Garros championship helped Djokovic surpass Nadal in the number of Grand Slam titles, when the Serbian tennis player owns 23 titles, one more than Nadal, who has spent most of this year recovering from injury.

Federer was not convinced when asked if Djokovic was a GOAT of sorts in men’s tennis. He shared his thoughts on the Halle Open, a tournament he has won 10 times as a guest: “Which is better, winning Wimbledon at 17 like Boris Becker or winning Roland Garros at 36 like Djokovic? I’m not sure.”

Federer’s comparison was a reference to Becker’s first Grand Slam title, which he won unseeded in 1985 and became the first German to win Wimbledon. Becker was also the youngest male Grand Slam winner at the time, aged 17 years and 227 days (Michael Chang later broke the record in 1989, winning Roland Garros at 17 years and 110 days).

Of course, Federer has no intention of downplaying the achievements of Djokovic, one of the two remaining members of the Big Three that have dominated tennis for years. The former Swiss still considers Nole’s titles a great step forward. But Djokovic’s GOAT status cannot be definitively answered until Nadal officially hangs up his racquet.

“What Nole has done is amazing. That’s enough for him to be recognized. But as long as Nadal is still playing, it’s hard to give a convincing answer,” FedEx concluded.