This year, as the fall football season was beginning and the summer tennis season was drawing to a close, two of these sports’ brightest stars, Andrew Luck, the Indianapolis Colts All-Pro quarterback, and Novak Djokovic, the defending U.S. Open tennis champion, found themselves booed by fans who once cheered them.

What Luck and Djokovic had done was announce that because of injuries they were withdrawing from competition. Luck’s decision was momentous. He told fans that he was retiring from professional football. Djokovic’s decision was limited to the U.S. Open. In the midst of his fourth-round match against Stan Wawrinka, Djokovic announced that the pain in his injured shoulder would not allow him to continue.

Sports fans are notoriously fickle, but the booing of Luck and Djokovic reflects more than fickleness. It is part of a cultural change in fan expectations. Fans are increasingly angry when star athletes let their personal lives (even when they involve health issues) interfere with their professional lives.

The wealth—widely reported these days—of athletes at the top of their profession has made it difficult for fans to identify or sympathize with them. Luck, at just 29, has made more than $97 million since entering the National Football League in 2012, and Djokovic, who is 32, has career earnings that total over $100 million.

The psychological distance fans feel from the players has been compounded by watching the players in action from a distance. The best seats in most sports venues are typically bought up by corporations and the wealthy. Most fans sit far from the field of play and rely on stadium Jumbotrons to show them close-ups of the action.

Pulling for a hometown favorite in football or a personal favorite in tennis remains a motive for many, but increasingly it is not just a favorite whom fans are rooting for. They are rooting for the team or individual player they have wagered on. Legalized sports gambling, aided by the Supreme Court’s 2018 decision striking down the Professional and Amateur Sports Protection Act, is on the rise. Electronic betting and games with substantial payoffs, like Fantasy Football, are now widespread. When a player such as Luck retires or a Djokovic withdraws from competition, there is a good chance that he is costing a fan who bet on him money.

The irony is that if any two professional athletes have given their fans grounds for identifying with them rather than resenting them, it is Luck and Djovokic. 

A Stanford graduate and son of a former National Football League player, Luck was a four-time Pro Bowl selection for a team that offered him little protection from opponents’ defenses. Luck’s list of injuries over just six years of play—he missed one season entirely due to injury—included a lacerated kidney, a concussion, a torn labrum in his shoulder, and most recently ankle pain that would not go away.

“I haven’t been able to live the life I want to live. It’s taken the joy out of the game,” Luck declared in explaining his retirement one season after being voted the National Football League’s comeback player of the year. In a year in which after just four games starting NFL quarterbacks have suffered injuries ranging a concussion to a broken clavicle, Luck’s decision is looking more and more like the right one.

Djokovic’s profile is a similar combination of success and grit. His first Grand Slam win was at the 2008 Australian Open, and from January 2015 to June 2016, he won five out of the six Grand Slams. This amazing winning streak was followed by a lengthy struggle with an elbow injury, but in 2018 he bounced back to win Wimbledon, and this year he won Wimbledon again, defeating Roger Federer in the longest finals match in the history of the tournament. “I’m sorry for the crowd. Obviously, they came to see a full match,” Djokovic observed in ending his run in this year’s U.S. Open.

So far there has been no significant backlash against those who booed Luck and Djokovic. The mood of resentment that has occupied so much of our political discourse in recent years has found a place in the sports world. President Donald Trump was moving with, not against, the tide of public opinion when in 2017 in response to National Football League players taking a knee during the National Anthem in order to protest racial injustice, he told a rally of his supporters, “Wouldn’t you love to see one of those NFL owners, when somebody disrespects our flag, say, ‘Get that son of a bitch off the field right now. Out! He’s fired!’”

Trump’s message, like that of the fans booing Luck and Djokovic, was clear: These men don’t know their place. Given the money they have been paid, they should suck it up and focus on their playing.  The irony is that never have pro athletes been more aware of the dangers of playing their sport. They rely on their unions to bargain for them on safety issues, and those who can afford it often turn to their own doctors rather than team doctors when it comes to medical advice.