Former NFL running back Thomas Jones plans to donate his brain after his death to be studied on the impact of concussions on football players.
Thomas is concerned about how chronic traumatic encephalopathy (CTE) might affect him in the future, ESPN.com reported. Jones wasn't sure how many concussions he had suffered during his career.
"Honestly, like I couldn't give you a number because you just play with them," Jones told ESPN.com. "You can't know; nobody does. I think the guys counting the concussions were the ones that got knocked out."
Jones retired from the NFL after the 2011 season. He rushed for 10,591 yards on 2,678 carries in 180 games with the Arizona Cardinals, Tampa Bay Buccaneers, Chicago Bears, New York Jets and Kansas City Chiefs.
ESPN.com reported that the Sports Legacy Institute has more than 600 living athletes who want to donate their brains for studies. Current data indicated that of 34 players who have donated brain tissue samples, 33 have shown evidence of CTE. The tests can only be done after death.
The family of former San Diego Chargers linebacker Junior Seau said last week that his brain showed evidence of CTE. Seau committed suicide last year.
Jones is working on a documentary series "The NFL: The Gift or the Curse?" that focuses on concussions and suicide, domenstic violence and financial pressures.