The Serbian is in good company, as Roger Federer failed to win at the 2004, 2008 and 2012 Olympics despite being ranked number one.
Federer’s victory with Stan Wawrinka in the 2008 doubles in Beijing does make the trophy cabinet that little bit shinier, but the 35-year-old Swiss will undoubtedly waltz into retirement without a singles triumph in the Olympics to his name.
Switzerland's Stanislas Wawrinka (R) and Roger Federer (C) stand with their gold medals during the medal ceremony for the men's tennis doubles at the Beijing 2008 Olympic Game
Image credit: Reuters
With Djokovic aged 29, questions will be raised as to whether he has another Games in him, and there’s no telling where he will be ranked come Tokyo in 2020.
These two goliaths of tennis are not alone, as Sydney 2000 saw then world number one Marat Safin crash out as fifth seed Yevgeny Kafelnikov took gold.
And while we’re going down the list, 1992 was the time of Jim Courier, but he fell in the third round while the unseeded Marc Rosset – who never reached a Grand Slam final - won gold.
You missed out 1996…
Why yes, the exception to this world number one rule comes in both 1996 and 1988, and for good reason, as the number ones at the time, Ivan Lendl and Pete Sampras, did not compete.
For Sampras, it was defeat in 1992 and a disdain for the Olympic tennis setup which led to him withdrawing in 1996.
Pete Sampras was critical of the Olympic setup before withdrawing in 1996
Image credit: AFP
Lendl meanwhile, was enduring a personal battle of his own, vying for American citizenship while still officially a Czechoslovakian. His path to represent USA in 1988 was blocked, and the eight-time Grand Slam champion never got to appear in Seoul.
In their respective absences, ’88 gold was snapped up by another Czechoslovakian, Miloslav Mečíř, while Andre Agassi beat a depleted field to win in Atlanta.
Agassi’s ’96 victory in Sampras' absence makes him the only player seeded first at the Olympics to go on and claim gold since 1988.
But why just one in eight?
So often with the Davis Cup, seeds and rankings seem to go out the window, as national pride and the fervour derived from a different environment appears to bring out the best in the most average of players.
It seems that the Olympics has the same impact, and while losing to Del Potro is understandable, the playing field appears to level itself out when a medal is at stake.
Indeed, Federer found himself losing to an 18-year-old Tomas Berdych in 2004 and the speedy American James Blake in 2008 before losing to Andy Murray in the London 2012 final.
While you could argue that Olympic gold is not the ultimate dream of an up-and-coming tennis player, a tournament is still a tournament nonetheless, and the inability of the world number ones to raise their level above the pack is highly questionable, and one that will no doubt be asked when Toyko rolls along as well.