That is the view of former World No 1 Mats Wilander.
Wilander, who won seven Grand Slam singles titles in his career, believes Novak Djokovic winning at Roland Garros it would be “the most impressive thing we have ever seen” in tennis.
The 32-year-old previously completed the achievement of holding all four slams back in 2016 at the French Open when he beat Andy Murray in the final and he now has the chance of doing it for a second time.
Djokovic, who entered the tournament as World No 1, will be aiming for a 16th Grand Slam win as he hopes to stop Rafael Nadal in Paris.
Although rivals Roger Federer and Nadal have more Grand Slam titles than Djokovic, with 20 and 17 respectively, neither of them have managed the feat of holding all four at the same time.
“In the grand scheme of things Novak winning four in a row again, it would be the most impressive thing we have ever seen,” Wilander said.
“If Novak wins the French, suddenly then he has to be compared to the greatest players of all time.
“He will have 16 (slams) if he wins the French. Okay Roger will still have 20 but it would be comparable because he would have won the Nole Slam twice, I mean that’s unbelievable.
“To me that’s incredible, Novak winning here is a bigger deal than Rafa winning 12 (French Opens).
“But then if Rafa wins, he’s on 18 majors so it’s getting crowded at the top.”
If Djokovic is victorious in Paris then he will become just the second player in tennis history to hold all four Grand Slam championships at the same time on two occasions.
The first to accomplish such a feat was Rod Laver in 1962 and 1969.
But ahead of the tournament, Djokovic insisted Nadal was the one to beat after losing to the Spaniard in the Italian Open recently.
“Nadal, number one favourite, without a doubt — then everyone else,” he said.
However, if Djokovic is successful in France, Wilander believes it could be the catalyst for the Serbian to go on and surpass Federer’s tally.
“If Novak wins I mean the door will be wide open to reach 20 Grand Slams, he added.
“Then if he equals Roger’s 20 he would be regarded as the greatest player of all time.”