Anna, Welcome to Neurotalk.

There is extensive experience with concussions and soccer.

The issue is simple. A soccer player should never head the ball.

A dangerous area is in the goal box during corner kicks when headers or high kicks are common.

In some states, heading the ball is not allowed during school soccer team games, especially at 14 yo or younger.

I have personal experience as a 15 year old sophomore. I suffered a head trauma from heading the ball that was a life changer. It caused a decrease in academic performance and caused a mild seizure disorder. I regained most of my functions over the next year but never recovered some cognitive functions and became photosensitive (bright lights).

I switched to cross country and track and excelled.