Marshawn Kneeland was a rookie defensive end for the Cowboys, a guy who was still building his NFL career when he died by suicide in November 2025. He was 24. Now, months later, the news gets even harder to sit with: researchers have posthumously diagnosed him with Stage 1 CTE.
Former Cowboys defensive end Marshawn Kneeland has been posthumously diagnosed with CTE. https://t.co/VRKGOAeqJd
The diagnosis came from Boston University's CTE Center, the same lab that has become the sport's unofficial clearinghouse for the disease's grim math. Stage 1 is the mildest classification on their 1-to-4 scale, which somehow makes this worse to process — a 24-year-old, barely a season into his pro career, already showing damage typically associated with much longer exposure to the game.
SleeperNFL laid out the details: Stage 1 CTE, confirmed by BU's CTE Center, on a 1-4 severity scale.
Kneeland's case lands in a league that's spent the better part of a decade trying to reckon with what football does to the brain, from Aaron Hernandez to Junior Seau to the youth-football data that keeps trickling out of BU's lab. There's no clean answer here, no obvious villain — just another name added to a list that keeps growing, and a reminder that this conversation isn't going away just because the season starts back up.