Novak Djokovic and Fellow Star Vaccine Skeptics Are Increasingly Scorned

In a less dangerous time, a more forgiving public viewed Novak Djokovic’s nontraditional views of science and health as the quirky characteristics of a hyperactive seeker with strongly held beliefs about everything from sports to spirituality.

He has sat inside a pressurized, egg-shaped pod during major tournaments, believing it would improve circulation, boost his red-blood cell production and rid his muscles of lactic acid. He supported the concept that prayer and faith could purify toxic water. Djokovic and other high-profile athletes with unorthodox approaches to health were a source of bemusement for a public that, for better or for worse, has long treated them as role models. These quirks as seemingly harmless as a bowl of quarterback Tom Brady’s avocado ice cream.

Not anymore.

Djokovic, an outspoken skeptic of vaccines, will spend the weekend detained in a hotel room in Melbourne, Australia, waiting out a legal appeal and expected hearing on Monday in hopes of gaining entry to the country following a public and political outcry over the medical exemption he received to play in the Australian Open without being vaccinated. The Australian Border Force rejected his paperwork supporting that exemption on Wednesday.

The pitched battle over what was supposed to be his quest for a record 10th Australian Open men’s singles championship has highlighted a new dynamic for stars like Djokovic. The latest surge of coronavirus cases and the ongoing struggle to exit the pandemic have shifted public perceptions: Athletes once viewed favorably as iconoclasts are now encountering pushback when they want to play by different rules than everyone else.

“The general public continues to respond positively if an athlete is speaking out on topics that make a difference in society and make peoples lives better,” said Michael Lynch, the former director of sports marketing for Visa and a longtime consultant to the sports industry. “But if someone takes a position that put peoples’ lives at risk, then they are going to have very negative reaction.”

The fame that comes with athletic success has provided Djokovic and other top athletes who oppose the coronavirus vaccines, like the N.F.L. quarterback Aaron Rodgers and the star basketball player Kyrie Irving, with platforms to promote causes they believed in and to collect millions of dollars to promote products. But in recent months, their high profiles have become a liability as their behavior and their views supported misinformation and put public safety at risk.

For sports organizations and leagues, the stakes are high. For more than a decade, access to social media has given sports stars the ability to become more outspoken and impactful than ever. As long as what they say has not been offensive or polarizing, they provided free, mostly positive publicity for their sports, their causes and their own brands.

The vaccination issue has changed the equation for sports, whose return in 2020 was viewed positively when they modeled safe behavior, such as mask wearing, playing before sparse crowds or no one at all, and participating in regular testing. The behavior and outspokenness of Djokovic, Rodgers, Irving and others against vaccines has jeopardized that good will, and organizations are now tightening their rules to play defense.

The N.C.A.A. said on Thursday that, in many instances, it would not consider players or coaches “fully vaccinated” unless they had also received a booster shot.

Although the guidance is not binding on schools and conferences, it is influential, especially with the N.C.A.A.-run Division I basketball tournaments scheduled to begin in March.

“You’re allowed to have your own beliefs, but once those beliefs start to impact other people, that is where things begin to get a little dodgy,” said Patrick McEnroe, the former professional tennis player who is now a commentator for ESPN.

That dynamic came to a head in Australia on Wednesday when federal border police detained Djokovic at a Melbourne airport.

Djokovic, a Serb who has won 20 Grand Slam tournament singles championships, had flown to Australia to defend his title in the Australian Open following the announcement that he had received a medical exemption from receiving a vaccine for an undisclosed reason. The exemption came from two panels of medical experts working on behalf of the organization that stages the tournament and the government of Victoria, the state that includes the tournament site, Melbourne. But while Djokovic was en route to Australia from Dubai, the public and some politicians began to voice their anger that Djokovic, the No. 1-ranked men’s tennis player, had seemingly received unjustified special treatment.

Roughly 80 percent of Australians have received at least one dose of a vaccination. Australians have endured some of the most stringent prohibitions to prevent the spread of the virus, including lockdowns that…