Serbia's Novak Djokovic returns to Italy's Matteo Berrettini during their men's singles final match on the thirteenth day of the 2021 Wimbledon Championships at The All England Tennis Club in Wimbledon, southwest London, on July 11, 2021. (ADRIAN DENNIS / AFP)

Fresh off his Wimbledon victory, world No 1 Novak Djokovic announced Thursday that he will participate in the Summer Olympics in Tokyo.

"Cannot disappoint my little friend Koujirou. I booked my flight for Tokyo and will proudly be joining #TeamSerbia for the Olympics," Djokovic posted to Twitter, referencing Kojiro Owaki, a 6-year-old Djokovic has corresponded with through social media and texts.

Djokovic earned his record-tying 20th career Grand Slam title last Sunday in England, afterward saying he was still undecided about playing in the Olympics.

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Djokovic could become the first male tennis player to achieve the Golden Slam - winning all four Grand Slams and the gold medal in men's singles at the Olympics in the same calendar year.

Djokovic has the first three under his belt. The US Open begins late next month in New York.

Steffi Graf is the only woman to have done it, in 1988.