Just so we’re clear on this: I still love football. I love the grace and the poise of the athletes. I love the tension between the ornate structure of the game and its improvisatory chaos, and I love the way great players find opportunity, even a mystical kind of order, in the midst of that chaos.

The problem is that I can no longer indulge these pleasures without feeling complicit. It was easier years ago, when injuries like Stingley’s could be filed away as freakish accidents. TV coverage was relatively primitive, the players hidden under helmets and pads, obscured by fuzzy reception, more superheroes than men. Today we see the cruelty of the game in high definition. Slow-motion replays show us the precise angle of a grotesquely twisted ankle and a quarterback’s contorted face at the exact moment he is concussed.

The sport’s incredible popularity has turned players into national celebrities and has made their mental and physical deterioration front-page news. In 2012, the former All-Pro linebacker Junior Seau killed himself. The autopsy confirmed that he had chronic traumatic encephalopathy, or C.T.E., the cause of the dementia that is increasingly prevalent among former players. A whole new crop of retired stars, including Tony Dorsett and Brett Favre, are just beginning to report symptoms like memory loss and depression.