IRVINE, Calif. — Outside of injury, it’s the cruelest part of sports.

But it’s the unforgiving reality facing the U.S. national team as the World Cup knockout stage begins.

What happens next matters much more than what was just accomplished.

What happens next will either enhance all the good that this U.S. team has done in this World Cup and allow bigger dreams to percolate … or it will erase it all — in the blink of 90 minutes.