NFL stars Steve Weatherford and Sidney Rice have promised to donate their brains to medical research after their deaths.
The duo made the decision in order to help learn about and even prevent diseases that have affected a number of former American football players.
Rice, who won the Super Bowl last year with the Seattle Seahawks, retired at the age of 27 shortly after the final due to fears of suffering long-term health problems following numerous knocks to the head.
"I had my fair share of fun in the NFL," BBC Sport quotes Rice as saying. "Unfortunately, I wasn't educated enough on what concussions can lead to. The brain studies by the doctors will be huge to help, maybe prevent."
Around 4,500 former players are suing the NFL over head injuries suffered while playing.
