Larry Johnson was the Chiefs' 2003 first-round pick. He had back-to-back 1,700-yard rushing seasons in 2005 and '06 -- those were the only times he cracked 1,000 yards -- but Kansas City released him midway through the 2009 campaign. By 2011, after stints in Cincinnati, Washington and Miami, Johnson was out of the league.

More than six years removed from his last NFL snap, the 38-year-old is apparently convinced that he has chronic traumatic encephalopathy (CTE), the chronic brain disease caused by repeated blows to the head. CTE can only be diagnosed after death but Johnson cites mood swings, memory lapses, headaches and violent and self-destructive impulses -- all symptoms of CTE -- as reasons why he's concerned.

Johnson calls them "blank spots," and he has taken to creating a "time capsule" of his football career for his seven-year-old daughter in case he ever gets to the point where he is no longer capable of remembering the specifics of his life.

"If I can't remember who I was, I've got YouTube; I've got music videos that I'm making for myself, so when I watch these things I can remember," Johnson told Kent Babb of the Washington Post. "I'm trying to get these things in order so she knows who I am and what I came from."

Johnson felt a sense of urgency to complete the time-capsule project in recent months after former Patriots tight end Aaron Hernandez committed suicide in his prison cell. Jose Baez, a lawyer for Hernandez, said researchers determined that Hernandez's case was "the most severe case they had ever seen in someone of Aaron's age." Hernandez was 27.

"I could be Aaron Hernandez," Johnson said.

"A bittersweet thing: I'm going to be free of everything that's holding me down," he said. "The same way Aaron [Hernandez] thought: I'm going to be gone from this world, but I'm still going to be able to take care of my child, because that's all I care about."

Johnson says his daughter is the only reason he hasn't acted on his violent tendencies.

"She's, like, a good distraction I have," he said. "She sees something in me that most people will never see."