By Ajai Masand New Delhi, July 21 : Among the sports that have seen the most number of high-profile withdrawals at the Tokyo Olympic Games, tennis would probably rank highest on the list. Among the sport, the world is still going to follow despite so many high-profile pull-outs, tennis would probably rank among the top. Such is the aura of the sport that Roger Federer, Rafael Nadal and Venus Williams not being there in Tokyo will not stop people from watching the tennis event at the Olympics and talking in glowing terms about the Swiss and Spanish greats and the Williams sisters' exploits at the quadrennial games. While the conversation will most certainly veer around the Williams sisters, who each have won four gold medals since making their Olympic debuts in 2000 but are skipping the Olympics, there will also be a lot of interest around Serbia's Novak Djokovic, who is bidding to become the first male player to pull off a calendar golden slam. Only Germany's tennis legend Steffi Graf has achieved the feat of winning all four grand slams and the Olympic gold in a calendar year -- 1988 -, and while three more have achieved a career golden slam - Serena, Andre Agassi, and Nadal - none has managed a calendar slam. Djokovic, winner of the Australian Open, French Open, and Wimbledon recently will have the Olympic gold firmly in sight before he aims for the US Open title in August-September to achieve the ultimate prize. The 34-year-old world No. 1 Serb is in imperious form and, having won his 20th Grand Slam title to become the joint world record holder with Federer and Nadal has fuelled his desire to set the bar higher. A bronze medallist at the 2008 Beijing Olympic Games, Djokovic was initially in two minds after winning the Wimbledon recently whether to compete in Tokyo or not. But now that he is competing, the Serb is the frontrunner for gold. If things go according to script and Djokovic meets Greece's Stefano Tsitsipas in the final, it could be a déjà vu moment for the Serb, who had beaten the world No. 4 in the Roland Garros final this year. Or, perhaps, it could be Russia's world No.2 Daniil Medvedev, who will make his Olympic debut in Tokyo. There are plenty of permutations and combinations if one throws in the likes of Germany's Alexander Zverev, Argentina's Diego Schwartzman, and Great Britain's two-time Olympic gold medallist Andy Murray, though Djokovic will continue to be the favourite to win his maiden Olympic gold. Japan's Naomi Osaka, currently ranked No.2 in the world, could make the Tokyo Olympics tennis arena the springboard to return to peak form following her mental health issues, which saw her pull out after the first-round win at the French Open and the Wimbledon. The women's event could be a three-horse race with Wimbledon champion and world No. 1 Ashleigh Barty of Australia, Naomi, and the Czech Republic's French Open singles and doubles champion Barbora Krejcikova in contention for gold. The United States, which has won 39 medals, including a record 21 of them gold in Olympic tennis, is unfortunately not among the favourites in Tokyo with the Williams sisters not competing. Such was the dominance of Serena and Venus at the Olympics that they each have four gold medals since making their Olympic debuts in 2000. They won three gold medals together, with Serena winning the singles gold in 2012 and Venus winning the singles gold in 2000 and mixed doubles silver with Rajeev Ram in 2016. There was hope from 17-year-old Coco Gauff, but following her pull-out due to Covid-19, the US team wears a sparse look. /IANS