Junior Seau's suicide on Wednesday comes as more than 1,200 former professional football players sue the NFL, saying the league concealed a link between concussions and what one top expert calls "mental disease" in players.
» Sign Up For Breaking News Alerts» Like Us On Facebook» Follow Us On Twitter
For Seau family friend Joe Gallagher, it was a comment Seau made recently that almost went unnoticed.
"Junior had wanted to donate his brain to science to the study of concussive injuries," said Gallagher.
Seau's death follows that of former Pittsburgh Steeler Terry Long, former Atlanta Falcon Ray Easterling and former Chicago Bear Dave Duerson.
Duerson also wanted to donate his brain to science. He left a suicide note talking about his desire to learn more about football-related head injuries. Like Seau, he shot himself in the chest.
"There's no question in my mind that is directly linked to brain injury," said Dr. Daniel Amen, a Newport Beach brain doctor who has studied NFL brain injuries and is convinced suicide and brain trauma are linked.
His analysis supports a Boston University study which found at least 20 retired NFL players with brain disease after they finished their careers.
Amen treated more than 100 former NFL players and said a brain injury can be rehabbed like other injuries.
"What we see is 80 percent of our players show high levels of improvement after just a couple of months," he said.
But Duerson, Long and Easterling never got help. The medical examiner's report said Long's history of brain injury was "a significant factor" in his death.
When Easterling shot himself, his wife described him as being badly damaged both physically and mentally from his playing career.
Gallagher said he never saw those signs in his friend.
"If you had told me this weekend when I saw him, I wouldn't have believed it," he said.
Copyright Do you have more information about this story? Click here to contact usCopyright 2012 by 10News.com. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.