It was only six years ago when Federer’s then tally of 17 Grand Slam titles looked well out of Djokovic’s reach, who then had just the five.
But the Serbian has gone from strength to strength over the ensuing years, winning 11 Grand Slam titles, including four of the last five.
He heads into the US Open aiming to defend his 2018 crown and opens his tournament with a first round match against Roberto Carballes Baena on Monday.
A fourth career win at Flushing Meadows would take Djokovic to 17 Grand Slam titles, just one behind Rafael Nadal and three back from Federer.
The latter hasn’t won at the US Open since 2008 and was knocked out in the fourth round last year.
Djokovic also has age on his side being six years younger than Federer and at his current rate, many are asking the question as to whether the 32-year-old can become the new all-time leader in Grand Slam titles on the ATP Tour.
And the world No 1 admits himself that he has made that target one of his personal goals.
”I’m aware of [the debate around the Grand Slam titles leaderboard],” he said.
“I mean, I’m part of this world.
“Of course, I can’t completely switch off and eliminate what people are talking about.
”It’s flattering, obviously. But at the same time, you know, it’s still a very long way ahead of me.
“It does also put a certain level of responsibility to me as well, because I am aiming to do that.
“It’s definitely one of my ambitions and goals.
“Especially now, more or less everything is about Grand Slams, in terms of how I see tennis and how I approach them because they matter the most.”
“I am 32, so things are a little bit different than they were 10 years ago, but I still feel young inside and outside.
“I am still very motivated to keep going.”
