Serbia's Novak Djokovic serves to Italy's Lorenzo Musetti during a match of the Dubai Duty Free Tennis Championship in Dubai, United Arab Emirates, Feb 21, 2022. (KAMRAN JEBREILI / AP)

There is a petition circulating to allow Novak Djokovic to play at the US Open but the Serbian appears likely to miss the entire North American hardcourt swing barring a sudden change in COVID-19 protocols in the United States and Canada.

Djokovic has refused to take the COVID-19 vaccine yet the 21-times Grand Slam winner remains on the entry lists for the ATP 1000 events in Montreal and Cincinnati that serve as tune-ups for the Aug 29-Sept 11 US Open in New York

Djokovic has refused to take the COVID-19 vaccine yet the 21-times Grand Slam winner remains on the entry lists for the ATP 1000 events in Montreal and Cincinnati that serve as tune-ups for the Aug 29-Sept 11 US Open in New York.

In the case of the US Open, which does not have a vaccine mandate, organizers previously said that per the Grand Slam Rule Book, all eligible players are entered into the main draw based on their ranking 42 days prior to the first Monday of the event.

US Open organizers also said that while they do not have a vaccination mandate in place for players, they will respect the US government's position regarding travel into the country for unvaccinated non-US citizens.

Former world number one Djokovic, whose website shows no upcoming events, said last week he was preparing for the US Open as if he will be allowed to compete in the year's final Grand Slam despite not being vaccinated.  

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Djokovic's camp and organizers of the three North American hardcourt events did not immediately respond when asked by Reuters on Tuesday for comment.

The hashtag #LetNovakPlay was circulating on social media as a slew of Djokovic supporters voiced their support for a player who moved to within one of Spaniard Rafa Nadal's record of 22 Grand Slam titles after his Wimbledon triumph last month.

"Tennis is not interesting or authentic when the best are not allowed to compete," one Twitter user wrote while another felt winning a tournament where Djokovic is not able to play is less impressive: "There will be an * after every tournament winners name where Novak isn't allowed to play!"

An online petition that launched a month ago calling for the United States Tennis Association to work with the US government to allow Djokovic to compete in the US Open was edging closer to its target of 50,000 signatures on Tuesday.

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The focus on Djokovic's status ahead of a Grand Slam is far from new as he was unable to defend his Australian Open crown this year after being deported from the country over his vaccination status in January.

Djokovic has previously said he was prepared to miss Grand Slam tournaments rather than take the COVID-19 vaccine.