The impact of concussions is now impacting Major League Baseball.
A former Kansas City Royals player Ryan Freel has been diagnosed as the first baseball player with chronic traumatic encephalopathy, or CTE. He committed suicide back in 2012.
Freel played for the Royals for part of the 2009 season, after spending most of his career with the Cincinnati Reds.
During his eight year career, he suffered up to ten concussions.
His mother says even today she wonders if she could have done more to save her son.
"Even the day before he took his life, I went to his house, and I remember he was in bed, and I held his hand, and I said, ‘son, let's go to a counselor,'" she told CNN.
Major League Baseball says its working with experts to prevent concussions.