Novak Djokovic said that he will not be able to compete at the hard-court tennis tournaments in Indian Wells, California, or Miami because he is unvaccinated and can’t travel to the United States.

The 20-time Grand Slam champion tweeted Wednesday that the Centers for Disease Control “confirmed the regulations won’t be changing so I won’t be able to play in the U.S.”

Djokovic, who recently dropped to No. 2 in the ATP rankings, has played in only one tournament so far in 2022 because he has not received any shots to protect against COVID-19. He was deported from Australia in January and was not allowed to try to defend his title at Melbourne Park.

Rafael Nadal wound up winning the Australian Open for his 21st major trophy, breaking a tie with Djokovic and Roger Federer for the most claimed by a man in the history of tennis.

Djokovic is a 34-year-old from Serbia who said in April 2020, as the coronavirus pandemic raged, that he was opposed to needing to be vaccinated to travel. In June of that year, with professional tennis on hiatus, he organized a series of exhibition matches in Serbia and Croatia with no rules requiring social distancing or masking — a tour that was called off after some players, including Djokovic, got COVID-19.

His name was put in the draw for the BNP Paribas Open in California on Tuesday, even though his status was up in the air because the U.S. has been requiring foreign visitors to be vaccinated to enter the country. In addition, the tournament had previously announced that everyone on-site at Indian Wells would need to be fully inoculated.

“While I was automatically listed in the @BNPPARIBASOPEN and @MiamiOpen draw,” Djokovic wrote Wednesday, “I knew it would be unlikely I’d be able to travel.”

Indian Wells is under way this week; the Miami Open starts on March 21.

“We understood from the beginning that Novak’s participation at the Miami Open was determinant on his entry into the United States, which we knew would be a long shot,” said James Blake, the tournament director in Miami. “We have an incredibly deep and talented player field, and look forward to hosting a great event.”

Chris Widmaier, a spokesman for the U.S. Tennis Association, which runs the U.S. Open, said the organization would have no comment other than to note that the event follows government guidelines. The American Grand Slam tournament is scheduled to begin on Aug. 29.

It has been a turbulent start to 2022 for Djokovic, who went through detention and a court case during an 11-day saga in Australia before he was sent home. During the legal back-and-forth, Djokovic said he wasn’t vaccinated and thought he should get a medical exemption to rules requiring the shots because, he said, he tested positive for COVID-19 again in December. He also said he attended an in-person interview with a reporter despite having that result.

In February, Djokovic said in an interview that he would not get vaccinated, even if he needs to be in order to participate in events such as the French Open or Wimbledon.

On the last day of last month, Djokovic dropped out of the No. 1 ranking for the first time in two years, sliding to No. 2 behind Daniil Medvedev. Djokovic’s 361 total weeks atop the ATP are a record, as are his seven times finishing a season at No. 1.

And on March 1, Djokovic announced that he and coach Marian Vajda were splitting up after 15 years together.

In his lone tournament of the year, Djokovic lost to Jiri Vesely in the quarterfinals of the Dubai Championships.