Former Cowboys Player Marshawn Kneeland Diagnosed with CTE

Marshawn Kneeland, a former defensive lineman for the Dallas Cowboys, has been diagnosed with stage 1 Chronic Traumatic Encephalopathy (CTE), according to research from the Boston University CTE Center. This diagnosis, made in November 2025, indicates that Kneeland is in the earliest stage of this degenerative brain disease associated with head trauma in contact sports.

Symptoms of CTE can include difficulties with attention, concentration, and headaches. Nearly 50% of players studied by Boston University who were aged 30 and above showed signs of CTE.

Kneeland, who was an early round pick from Western Michigan University, played 18 games for the Cowboys and has been vocal about the struggles former players face regarding head trauma. His family hopes that sharing his case will help raise awareness about CTE and the necessary steps to prevent it among athletes.