Calls grow for Dolphins QB Tua Tagovailoa to retire as he sustains another concussion

It was a routine run for a first down, the kind that quarterbacks do every week in the National Football League.

But Tua Tagovailoa of the Miami Dolphins leaned headfirst into the tackle, and the impact against the defender’s chest sent his head sharply to the left.

Afterward, he collapsed to the ground, with his right fist balled and raised into the air in what appeared to be a telltale sign of brain injury.

Later during the Thursday-night game, the Miami Dolphins made it official: Tagovailoa had suffered a concussion, the latest for the 26-year-old whose career had already come to be defined by his worrying history of brain injury.

Now, Tagovailoa’s concussion has prompted a dramatic response by fans and former players alike who have urged him to retire — a reflection of a growing awareness among the American public of the risks of the long-term brain damage that can follow hits to the head. Even a current coach has called for him to retire.