Novak Djokovic
Getty Images

World No. 6 Novak Djokovic has withdrawn from next week's Western & Southern Open in Cincinnati because of his COVID-19 vaccination status. The unvaccinated tennis star's participation in the US Open, which begins on Aug. 29, is still uncertain.

The hard-court tournament in Cincinnati is set to take place Aug 13- 21. At this moment, unvaccinated foreigners are not allowed to travel to Canada or the United States. Earlier this month, Djokovic had to pull out from the Canadian Open in Montreal. He also had to miss the Australian Open in January after being deported from the country due to his unvaccinated status.

Djokovic has won the US Open three times and was the runner-up last year, falling to Daniil Medvedev in the title game. The Serbian star has registered 21 major championships and is still fresh off his seventh career Wimbledon title. He only needs one more Grand Slam title to tie Rafael Nadal for the men's record, but he has already said publicly that he does not intend on getting the vaccine.

"I'm not vaccinated and I'm not planning to get vaccinated so the only good news I can have is them removing the mandated green vaccine card or whatever you call it to enter United States or exemption," Djokovic said after his Wimbledon win. "I don't know. I don't think exemption is realistically possible. If that is possibility, I don't know what exemption would be about."

Djokovic doesn't necessarily need to rule out the US Open yet, as the CDC could still change its guidelines to allow unvaccinated travelers into the country in the next few weeks.

"This updated guidance is intended to apply to community settings," reads the CDC page. "In the coming weeks CDC will work to align stand-alone guidance documents, such as those for healthcare settings, congregate settings at higher risk of transmission, and travel, with today's update."