Federer, Nadal threaten Djokovic bid for historic Slam
Paris, May 23: Novak Djokovic can become only the second man in history to have twice held all four Grand Slam titles at the same time with victory at the French Open.
However, a returning Roger Federer and rejuvenated Rafael Nadal will once again stand in his way.
World number one Djokovic completed his first private stranglehold of all four Slams with victory at Roland Garros in 2016.
Having clinched the 2018 Wimbledon and US Open titles and then a seventh Australian Open crown in January this year, the Serb is tantalisingly close to another 'Djoko Slam'.
Federer and Nadal, with 20 and 17 career Grand Slam titles each respectively, may be ahead of 15-time major winner Djokovic in total hauls and have also completed career Slams.
However, not even Federer or Nadal have managed to hold all four of the sport's greatest prizes at the same time.
It is such a rare feat that only Don Budge (1938) and Rod Laver (1962 and 1969) -- all calendar Grand Slams -- have pulled off the sweep in the sport's history.
Djokovic, who turned 32 on Wednesday, is playing down his potential date with destiny even if it would put him halfway to a 2019 calendar Slam of his own.
After losing to Nadal in the Italian Open final last weekend, the Serb was in no doubt that it was the Spaniard who would likely be celebrating a 12th Roland Garros title in a little over two weeks' time.
"Nadal, number one favourite, without a doubt -- then everyone else," he said.
Djokovic, who will be top seed in Thursday's draw, could be forgiven his caution.
At Roland Garros in 2018, he was shocked by Italian journeyman Marco Cecchinato in the quarter-finals, a defeat which was such a crushing bodyblow that he even contemplated skipping Wimbledon.
Federer is returning to Roland Garros for the first time since 2015 having turned his back on clay court tennis to focus on Wimbledon.