Marshawn Kneeland CTE became the headline no one wanted on Tuesday, when the family of the late Dallas Cowboys defensive end released the results of his posthumous brain analysis. Researchers at the Boston University CTE Center diagnosed the 24 year old with stage 1 chronic traumatic encephalopathy, the earliest of the disease’s four stages, after his family donated his brain for study. Kneeland died by suicide in November 2025, and his loved ones shared the findings through the Concussion and CTE Foundation with a statement that said more about who he was than how he died.
His girlfriend, Catalina Mancera, spoke for the family and refused to let the diagnosis flatten him into a cautionary tale. She said the finding does not change the tragedy of his passing but provides important context about some of the struggles he may have been facing, and that the family wanted people to understand what NFL players and other athletes in high contact sports might be carrying. They asked that Marshawn be remembered with compassion for the person he was, rather than defined by the final moments of his life. Mancera was pregnant when he died. She gave birth to their son last month.
That detail reframes the entire Marshawn Kneeland CTE story. This is not a lineman from a leather helmet era who played before anyone tracked head trauma. Kneeland was the Cowboys’ second round pick in the 2024 NFL Draft out of Western Michigan, and he played only 18 games across two seasons before his death. He came up inside the modern machinery of concussion protocols, sideline spotters and upgraded helmets, and researchers still found the disease in his brain. Dr. Ann McKee, who directs the Boston University CTE Center, said she was not surprised, because her team has found the same progressive brain disease in nearly half of the athletes they have studied who died before the age of 30.
Chris Nowinski, the Concussion and CTE Foundation CEO, put the warning in plain terms. He said Kneeland played in the era of concussion protocols and better helmets and developed CTE anyway, and that there is no reason to believe today’s players face a lower risk than previous generations. His point cuts against the comfortable assumption that better equipment solved the problem. CTE is driven by the accumulation of repeated head impacts, not only by the diagnosed concussions that make it into an injury report, which means the routine collisions of an ordinary practice week are part of the ledger.
The Marshawn Kneeland CTE finding sits at stage 1, the lowest rung on a scale of one to four, but the number should not read as reassurance. According to the CTE Society, even early stage CTE can present with short term memory problems, depression, aggression, difficulty controlling impulses and executive function issues, the kind of symptoms that are easy to mistake for something else in a young man’s life. That is the quiet danger the family is pointing at. The damage can be real and the person can still be told, and can still tell himself, that nothing is wrong.Both Boston University and the foundation were deliberate about one line, and it matters enough to repeat clearly. Suicide is complex and multifactorial, and a posthumous CTE diagnosis should not be treated as the cause of a suicide, nor is it a known risk factor for one. That distinction is where a lot of coverage gets careless. The honest version is that Kneeland had a brain disease and Kneeland was a person facing struggles, and the diagnosis adds context to his story without collapsing it into a single explanation. Records reviewed by ESPN show that concerns about his mental health had surfaced years earlier, dating back to his time in college, which speaks to how long these battles can run beneath the surface of a career that looks like it is ascending.
What the family chose to do with a private grief is the part worth sitting with. They could have kept the results to themselves. Instead they released them so that other athletes, other families and other young people in violent sports might recognize something in Kneeland’s story before it becomes their own. Mancera signed the family’s message with two words, One Love, and asked for privacy as they continue to grieve. The Dallas Cowboys honored Kneeland during the season, and the larger sport now has another name attached to a question it has spent two decades avoiding. He was 24. He had a son on the way. He did everything the modern game told him would keep him safe, and the disease was already there.
If you or someone you know is struggling, the 988 Suicide and Crisis Lifeline is available 24 hours a day by call or text at 988.
