MELBOURNE, Australia — When Australia’s prime minister explained on Thursday why his government had barred Novak Djokovic, the men’s tennis superstar, from entering the country, he described it as “simply a matter of following the rules” requiring coronavirus vaccinations for incoming travelers.
“People are put on planes and turned back all the time,” the prime minister, Scott Morrison, said.
But Mr. Djokovic, who had a visa to travel to Australia and a vaccination exemption to compete in the Australian Open, collided not just with the country’s tough border restrictions after arriving at a Melbourne airport. He also found himself at the center of a highly charged moment in Australia’s fight against the coronavirus.