For the second time this year, Novak Djokovic is being forced to skip a grand slam tournament. The tennis star announced Thursday that he won't play in the 2022 U.S. Open.

Djokovic is not allowed to travel to the United States because he is unvaccinated against COVID-19. The 35-year-old announced that he can't play in the tournament shortly before the field for the 2022 U.S. Open was set to be revealed.

"Sadly, I will not be able to travel to NY this time for US Open," Djokovic said in a tweet. "Thank you #NoleFam for your messages of love and support. Good luck to my fellow players! I'll keep in good shape and positive spirit and wait for an opportunity to compete again. See you soon tennis world!"

Djokovic won the last grand slam, defeating Nick Kyrgios in the Wimbledon final. It marked the 21st grand slam title in Djokovic's career, good for second all time.

After winning at Wimbledon, Djokovic said he was preparing as if he would be allowed to compete in the U.S. Open.

Rafael Nadal owns the record with 22 grand slam championships. Nadal defeated Djokovic in the French Open quarterfinals en route to his record-setting title.

Nadal also won the 2022 Australian Open. which Djokovic wasn't allowed to compete in because of his COVID-19 vaccination status. The No. 1 ranked tennis player in the world to start the year, Djokovic was deported from Australia when he tried to play in the event.

Djokovic was the runner-up at the 2021 U.S. Open. He's won the championship in Flushing Meadows three times and finished in second place on six occasions.

Djokovic won three grand slam championships last year.