Stephen Lovekin/Getty Images

Hall of Fame defensive lineman Warren Sapp wrote Tuesday on the Players' Tribune he plans to donate his brain to science in order to aid research into chronic traumatic encephalopathy (CTE).

Sapp, who played 13 years in the NFL, said the fact he's beginning to suffer from cognitive issues helped him make the decision:

"I've also started to feel the effects of the hits that I took in my career. My memory ain't what it used to be. And yeah, it's scary to think that my brain could be deteriorating, and that maybe things like forgetting a grocery list, or how to get to a friend's house I've been to a thousand times are just the tip of the iceberg. So when it comes to concussions, CTE and how we can make our game safer for future generations, I wanted to put my two cents in—to help leave the game better off than it was when I started playing."

Sapp also mentioned another Hall of Fame defender, former Miami Dolphins star Nick Buoniconti, who told Sports Illustrated's S.L. Price in May that he feels "like a child" as a result of his cognitive problems. Price wrote Buoniconti had PET scans done that were "consistent with Parkinsonian syndrome and CTE."

Doctors are only able to confirm a CTE diagnosis after examining a person's brain following his or her death, which is why former players such as Sapp have committed to donating their brains to CTE research.

This past April, ESPN.com's William Weinbaum and Steve Delsohn wrote Dr. Ann McKee, a researcher at Boston University, had examined the brains of 48 former NFL players. Forty-seven of the brains showed signs of CTE.

In September 2015, researchers from the Department of Veterans Affairs and Boston University said they had found CTE in 87 of the 91 brains they had studied belonging to former NFL players.