Novak Djokovic is nothing if not consistent. The 35-year-old Wimbledon champ won’t play in the U.S. Open for the same reason he didn’t compete in the Australian Open: He refuses to get vaccinated against COVID-19. Though the U.S. Open itself does not have specific vaccination requirements, the tournament announced in a statement that it “will respect the US government’s position regarding travel in the country for unvaccinated non-US citizens,” which stipulates that international travelers must be fully protected against the virus. As The Guardian reported, Djokovic was hopeful that the U.S. would let him compete following his Wimbledon victory. More than 12,000 hopefuls have signed an online petition asking the U.S. to allow Djokovic to play.