Conrad Dobler, once regarded as the dirtiest player in the NFL, had chronic traumatic encephalopathy (CTE) when he died in 2023 at age 72, his family and the Boston University CTE Center announced Wednesday.

Dobler, an offensive lineman and a three-time Pro Bowl selection in the 1970s, was diagnosed with Stage 3 CTE. There are four stages of CTE, a degenerative brain disease that can be diagnosed only after death.

CTE is associated with repeated blows to the head and symptoms such as depression and aggressive behavior.

“My dad loved the game of football, but his love for the game took a toll on his body, his mind, and his relationships,” Erin Lewin, Dobler’s daughter and described as Dobler’s primary caregiver for the final few years of his life, said in a news release issued by the Boston University CTE Center. “His CTE diagnosis provides a sense of closure in terms of justifying his neurological and behavioral issues that took a toll not only on him but on all of us who loved and cared for him.

“We are relieved to have a definitive answer and proud to honor his wish to go public with the findings to raise awareness for the risks of repetitive head trauma and for the research being done at Boston University.”

In a 2016 interview with USA TODAY Sports, Dobler said he was struggling with his memory and motivation levels.

“I have six kids, I don’t even know their names,’’ Dobler said during a phone interview. “It kind of pisses me off because I prided myself on having such a wonderful memory.’’

Dobler’s daughter Holli told USA TODAY in 2016 that her father at times struggled to control his emotions but it was difficult to know if that was part of his personality or the result of football-related brain trauma associated with CTE.

His NFL career spanned from 1972 to 1981, and a 1977 cover story in Sports Illustrated crowned him “Pro Football’s Dirtiest Player.” Dobler relished that reputation and his autobiography was titled, “They Call Me Dirty.”

He retired from the NFL after a 10-year career that included stints with the St. Louis Cardinals, the New Orleans Saints and the Buffalo Bills.

In 2010, Dobler pledged to donate to the Boston University CTE Center and took part in clinical research, according to the Center’s news release.

Upon Dober’s death Feb. 13, 2023, his brain was sent to the Center. Research revealed Dobler had a subtype of CTE called cortical sparing CTE that has earlier onset of behavioral symptoms but tends to have slightly less severe cognitive symptoms, according to the Boston University CTE Center.

“The support we have received from Conrad Dobler and the hundreds of former NFL players and their families who have participated in our research has put us on the cusp of diagnosing CTE in living people,” said Ann McKee, chief of neuropathology for the VA Boston Healthcare System and director of the Boston University CTE Center. “With continued support from the NFL player community, we will eventually be able to prevent future families from suffering the indignities and pain of CTE.”

This article originally appeared on USA TODAY: Conrad Dobler, longtime NFL player, had Stage 3 CTE