The NFL may struggle with everything from suicides to lawsuits over player injuries, but concern is now trickling down to the kids who play the game.

FOX News Radio's Jessica Rosenthal reports in the ninth installment of our ten-part series investigating the growing concern about concussions in the sport:

Former NFL quarterback Warren Moon was just a kid when he first hit his head playing the game.

(Moon) "Concussions start very early.  I had my first one when I was 11 years old."

More attention started going to kids as more attention was paid to the pros, but also after a middle school boy named Zach Lystedt suffered serious injuries returning too quickly to a game following a concussion.  Because of all of it, officials with Carson High School's team here in Southern California are having players take a pre-season test.

(Computerized Test) "When you see a repeating card, press the 'K' key for 'yes.'"

Kids must retake that test after an injury, before returning to play, and get pretty close to their pre-season score.  The school also has an athletic trainer.  Student-athlete Poi Tomeea says he hears about concussions a lot more now.

(Tomeea) "When I grow older, I don't want it to mess up my brain or anything, but I'm pretty sure it will, because of all this hitting we do every day."

Other players, like Daniel Cortez, who suffered a concussion last year, try not to think about it all.

(Cortez) "Thinking about that stuff, like, wouldn't really make me not want to play.  Like, I've been playing all my life.  Like, it is my life."

Jessica Rosenthal, FOX News Radio.

CLICK HERE for more of the FOX News Radio series "Head Games: The Dark Side of Football".

CLICK HERE to listen to the full FOX News Radio special "Head Games: The Dark Side of Football".