CHICAGO (CBS) — It’s the world’s most popular sport and now there’s new evidence that playing soccer can damage your brain.

CBS 2’s Mike Puccinelli has the story.

Joel Leon and Joel Salmeron have been playing soccer for most of their lives. They’re so good, earlier this month they helped lead the Morton High School Mustangs to the school’s first state championship in 25 years.

Salmeron said it was a “once in a lifetime feeling, you know, a good thing to experience. You know, you could tell your grandchildren about it. It’s just a great feeling.”

Salmeron scored the winning goal, but the Mustangs wouldn’t have made it to the title game if it wasn’t for Leon’s head.

“I stepped up for Supersectionals to send them to state,” he said. “I did that with my head.”

It was Leon’s header that sent Morton to the state semifinals, giving them a chance to win it all.

But now there’s new evidence that repeatedly heading a soccer ball can damage your brain.

“At this point in time, we clearly have evidence that heading may be related to changes similar to brain injury,” said Dr. Michael Lipton, a researcher at the Albert Einstein College of Medicine in New York City. Lipton and his team conducted a study of amateur soccer players.

According to the research, players who most frequently headed the ball showed abnormalities in five brain regions and players who headed the ball at least 1,000 to 1,500 times a year showed detectable brain damage.

But Leon said it won’t make him head the ball any less often.

“It will actually make me go in harder into a head to the ball,” Leon said. “That game-winning goal I did, that was a great experience because, I mean, I risked my head, but … look at where we got. We got first in state.”

While Leon isn’t overly concerned, Morton soccer coach Michael Caruso is.

“Anything that, you know, might cause injuries – especially to the head and your brain – should be looked at a little bit more,” Caruso said.

Caruso said the Illinois High School Athletic Association should monitor the research and determine if any changes need to be made.

“Whatever is best for the kids, is … you know, decisions have to be made around that,” Caruso said.

In the meantime, both Leon and Salmeron said they intend to keep their heads in the game.

“It’s just a game, it’s a passion for it, you can’t really change nothing of it, or else it’s not called soccer,” Salmeron said.