Serena Williams (tennis)

One cannot accuse Williams of diminishing the importance of the Olympics. After all, she is a four-time gold medallist, last winning the women’s singles title at the 2012 London Games. However, she will not compete at a fifth Olympics, saying there are “a lot of reasons” behind her decision.

Williams is reluctant to be specific but has previously been hesitant about playing in Tokyo because of the travel restrictions which barred her from bringing her three-year-old daughter, Alexis Olympia.

Williams, who will turn 40 in September, is still chasing a record-equalling 24th grand slam singles title but will have to wait until the US Open after she pulled out of Wimbledon mid-match in the first round because of injury.

Lin Dan (badminton)

The 37-year-old, who had clinched two Olympic gold medals and five world championships, had attempted to make his fifth Olympic appearance in Japan. However, his ranking was too far behind his compatriots – 2016 Rio champion Chen Long and rising star Shi Yuqi – for him to have a realistic chance of qualifying. Only two players in the top 16 from one nation can qualify for Tokyo.

Rafael Nadal (tennis)

The 35-year-old world number three decided not to participate at this year’s Wimbledon and the Olympic Games after “listening” to his body. He said there was only two weeks between the French Open and Wimbledon, which did not make it easy for his body to recuperate after the clay court season.

He is still determined to “prolong” his career and continue to compete at the highest level of tournaments. Top men’s player Dominic Thiem has also opted to skip the Tokyo Games.

Mo Farah (long-distance running)

Farah is one of the biggest names to have missed out. The four-time British Olympic champion failed to qualify to defend his 10,000 metres title in Tokyo. The 38-year-old, who won “double double” Olympic gold medals at 5,000m and 10,000m in London and Rio, missed the qualifying time of 27 minutes, 28 seconds by 19 seconds in a 10,000m race at the British athletics championships in June. He also missed the time at another British Olympic trial earlier that month, blaming a foot injury for his performance.

Dustin Johnson (golf)

The world number two in golf confirmed in March that he would not play in the Olympics, as the competition comes during a “big stretch of golf”. The travelling time is lengthy between the US and Japan and he would rather focus on the PGA Tour schedule over the Games.

The four-day men’s tournament, scheduled for July 29 to August 1, is only a week ahead of the World Golf Championships and two weeks before the start of the FedExCup play-offs. Johnson also opted to skip the 2016 Rio Olympics, citing concerns over the Zika virus.

Om Yun-chol (weightlifting)

North Korean weightlifter Om is a five-time world champion competing in the 56kg men’s category. As the London Olympic gold and Rio Olympic silver medallist, he has lifted triple his body weight to set two world records in clean and jerk and total in the 2019 world championships.

With North Korea declining to send a team for this year’s Olympic Games citing Covid-19 risks, Om will be unable to try for a third straight medal.

James Harden (basketball)

The guard at the Brooklyn Nets was reportedly withdrawn from joining the US team because of a hamstring injury he suffered during the NBA play-offs, after previously expressing an interest in making the trip to Tokyo as the United States vie for their fourth straight gold medal.

He was a Team USA member at the 2012 London Olympics and 2014 Fiba World Cup, taking gold in both events. He also competed for a sport on the 2016 Olympic team but was eventually left out.

Sun Yang (swimming)

The Chinese star has won three Olympic gold medals but was banned from competition in June because of his role in the breaking of a blood vial during an out-of-competition doping test at his home in Hangzhou in September, 2018.

His original eight-year ban by the Court of Arbitration for Sport was overturned after the Swiss Federal Tribunal found questionable social media posts from the panel judge. Although the ban was reduced to four years and three months, he will not be able to return to competition until just before the 2024 Paris Olympics.

LeBron James (basketball)

Along with Anthony Davis and Steph Curry, LeBron James was left out of the Team USA roster for the Olympics when the squad was announced in June. Having represented the US in 2004, 2008 and 2012, he has won three medals – two golds and one bronze.

The NBA superstar suffered an ankle injury in late March that forced him to miss a large chunk of the 2020-21 NBA session. He is set to star in the film Space Jam 2 this summer.

Carolina Marin (badminton)

The reigning women’s singles gold medallist is unable to defend her title because of a torn ACL and meniscus in her knee. The Spaniard thanked everyone for their support and promised that she will “certainly be back”.

She defeated India’s Pusarla V Sindhu in the 2016 final and became the first European woman to win a gold medal in Olympic badminton. Injury previously kept her out of the circuit for eight months, forcing her to miss the 2019 Worlds, where Sindhu won the title in Marin’s absence.