RIO DE JANEIRO (AP) ― Felled by an opponent’s knee to the head as they both chased the ball, a player is seemingly out cold on a World Cup pitch. The clock is ticking. Millions are watching. National honor, careers and sponsorship dollars are at stake.

Groggily, the player wakes up and argues furiously with his team doctor that he must play on. For anyone attuned to the dangers of concussions and head injuries, this is when alarm bells ring ― just as they did when this scenario unfolded at the World Cup in Brazil.

As in American football, team doctors should be able to pull a player off the field and calmly determine whether the player can continue. But that’s not easy when the player himself is yelling he’s OK and the doctors know that every minute they take is another minute the team must survive without that player.

And once a player is substituted, he can’t return.

To give doctors more time, the world union for footballers is arguing that soccer’s rules ― first codified 151 years ago in a London pub ― should be revised so teams can temporarily replace players while they’re examined for possible concussion.

“It might take a medical practitioner at least 10-15 minutes to properly diagnose a possibly concussed player, and symptoms/signs can take longer than that to show,” FIFPro said in emailed responses to questions from the Associated Press. “Teams and players should not be disadvantaged for upholding player health and safety, or encouraged to act in a way that compromises it.”