The clock is ticking on Novak Djokovic's prospects of playing at the US Open, two days out from the draw at Flushing Meadows.
Wimbledon champion Djokovic, who lost to Daniil Medvedev in last year's final in New York, has his route to the United States blocked by red tape at present.
US authorities are refusing to allow unvaccinated foreign visitors to enter the country, and barring a change of policy on that front, his hopes appear forlorn. Djokovic, a three-time US Open champion, has refused to accept any Covid-19 vaccine.
The United States Tennis Association (USTA) has pledged to adhere to government rulings surrounding coronavirus protocols, despite including Djokovic on the US Open entry list last month.
He remains on that list for now, but there was an indication that the US Open may not be expecting to see Djokovic when a promotional poster was revealed this week that featured four top women players and four leading men.
The men selected were defending champion Medvedev, 22-time grand slam winner Rafael Nadal, Australian Nick Kyrgios and Spanish teenager Carlos Alcaraz. All were archive pictures, so Djokovic could easily have been selected for the advertising campaign.
His exclusion prompted an angry response on social media from some fans of the 35-year-old Serbian, with one saying it would be "a failed tournament if he doesn't participate in it".
The US Open draws are due to take place on Thursday ahead of the start of the tournament on Monday.
Leading players are already assembling on site, with Medvedev, Serena Williams, Nadal, Alcaraz, Simona Halep and Andy Murray among those with practice sessions booked in for Tuesday.
For Djokovic to be allowed into the United States, it appears he would require a sudden change of entry rules from law-makers, or he would have to be considered suitable for an exemption.
In late July, he said he was "preparing as if I will be allowed to compete". However, he has not been able to travel for the build-up tournaments.
On Instagram, Djokovic's last tennis-related post came on Monday as he sent a congratulatory message to shock Cincinnati champion Borna Coric, telling the Croatian: "Bravo king! Totally deserved. All the effort and patience paid off. Go ahead and good luck."
Djokovic was not allowed to play at the Australian Open at the start of the year, when issues surrounding his visa ended with him being deported from Melbourne on public health grounds due to not taking the vaccine.
American great John McEnroe told Tennis 365 in July it was "crazy" that Djokovic should have to miss the US Open and called for a solution to be found.
The current entry rules in the United States were not in place when Djokovic was toppled by Medvedev in last year's men's singles final, ending his hopes of a calendar Grand Slam.
