Chronic traumatic encephalopathy (CTE), a debilitating condition caused by repeated impact to the head, was diagnosed for the first time in a major league soccer player — a case that has concussion awareness advocates calling for change in youth sports.

Taylor Twellman, former major league soccer MVP, said he knew the late major league soccer player Scott Vermillion, who was diagnosed with CTE after his death. Twellman said the head trauma that is endured during soccer should come as no surprise.

"In the sense that soccer now has CTE, you'd be naive to think that it wasn't there," Twellman told Jim Braude on Greater Boston.

Super Bowl champion Demaryius Thomas was also recently diagnosed with CTE. An official diagnosis can only be made after death.

Dr. Chris Nowinski, co-founder and CEO of the Concussion Legacy Foundation, said parents and coaches of youth sports need to know that the majority of head trauma in soccer is coming from hitting headers.

"The headers are the issue that's causing CTE, it's not just a random concussion here and there, and we have to be honest about that with people. We need to stop hitting children in the head," Nowinski said.

Nowinski himself was a professional athlete and said he likely has CTE.

Twellman and Nowinski are working together on safer soccer measures, such as taking players out of the game for an assessment after a blow to the head.

Twellman said he often attends youth sports games and noted that kids don't want to head the ball. "If I empower the kids, and we get the parents and coaches out of the equation, the kids are going to lead the change."

Watch: ‘We need to stop hitting children in the head:' concussion expert says after 1st soccer CTE case