PHILADELPHIA — Irv Cross was a man of faith and devout fan of football who could no longer in his final years attend Bible study or watch NFL games with friends. The degenerative brain disease that festered inside the former Philadelphia Eagles cornerback had triggered depression, mood swings and the type of memory loss that forced him into isolation.

"He really didn't want to be with people," said his widow, Liz Cross. "The only person he wanted to be with was me. When he was with me, he really didn't want to be with me. He just wanted me to be there."

Cross, the former NFL defensive back who became the first Black man to work full-time as a sports analyst on national television, is the latest football player diagnosed with the brain disease CTE. Cross, who was 81 when he died Feb. 28, 2021, suffered from stage 4 chronic traumatic encephalopathy, Boston University researchers said Tuesday.

Stage 4 is the most advanced stage of CTE, showing the kind of damage that often causes cognitive and behavioral issues in those exposed to repetitive head trauma. He struggled physically with his balance and was paranoid.

"Toward the end," Cross said, "he saw things that weren't there."

Cross said her husband, who was diagnosed with mild cognitive dementia in 2018, often sat in a chair and grimaced from headaches that weren't going away. He declined any kind of medicine because it didn't help the pain. He stopped going to church. Once a student of the game, NFL games were mostly background noise because he didn't know who was playing.

"He was afraid someone would ask him a question," Cross said, "and he wouldn't know the answer."

More than 300 former NFL players have been diagnosed with CTE

Irv Cross, of course, was not alone in misery among his former NFL brethren. According to its latest report, the BU CTE Center said it has diagnosed 345 former NFL players with CTE out of 376 former players who were studied, a rate of 91.7%. The disease can be diagnosed only after death.

"He was the nicest, kindest, most helpful, wonderful man I ever met," Cross said. "But that wasn't who he was at the end. And that wasn't who he was. It was the disease that did that."

Dr. Ann McKee, a professor of neurology and pathology at Boston University, said she was not surprised Irv Cross' brain reached stage 4 given the length of his overall football career (the study counted 17 years) and his age. Irv Cross and his family made the decision to donate his brain to help raise awareness of the long-term consequences of repeated blows to the head.

"I do think there's more education about the risks of football and I do think there's more awareness of concussion management but I still think we're way, way behind where we should be," McKee said. "We need to educate young athletes that this is a risk that they are undertaking. We need to educate coaches to keep head trauma out of the game. We need to do more managing of athletes by monitoring them better. I still think there's a very cavalier attitude toward CTE. There's a lot of denial."

In fact, Liz Cross said she and her husband were "both in denial" about the cause of the breakdowns in his health until about five years before his death.

"For somebody who had been so active and so able to do everything, and an athlete, not having balance, not having strength, not being able to do any of the things he had done before, it was embarrassing," she said. "He was pretty much in a constant state of depression."

One of 15 children from Hammond, Indiana, Cross starred in football and track and field at Northwestern. He was drafted in the seventh round by Philadelphia in 1961, was traded to the Los Angeles Rams in 1966 and returned to the Eagles in 1969 as a player coach for his final season.

The two-time Pro Bowl cornerback had 22 interceptions, 14 fumble recoveries, eight forced fumbles and a pair of defensive touchdowns. He also averaged 27.9 yards on kickoff returns and returned punts.

Chris Nowinski, the founder of the Concussion Legacy Foundation, said he met with Cross in 2018 and "it was very clear" the former Eagle was suffering.

"It's important to highlight cases like Irv Cross' because he was able to live a long and successful life where CTE didn't dramatically impair him," he said. "But at the end, it was a struggle."

Cross joined CBS in 1971, becoming the first Black network sports show anchor. He left the network in 1994, and later served as athletic director at Idaho State and Macalester College in Minnesota. In 2009, he received the Pro Football Hall of Fame's Pete Rozelle Radio-Television Award. He was married to Liz for 34 years when he died.

Cross never regretted his football career, his widow says

Cross said her husband never experienced regret over his football career.

"He would have done it again in a heartbeat," she said. "But he didn't think kids should play football."

As for diagnosed concussions, Cross said her husband told her he did suffer from several during his playing career but did not keep count. He suffered so many head injuries in his rookie season that his Eagles teammates called him "Paper Head."

Irv told his wife that after a blow to his head that almost caused him to swallow his tongue, doctors said if he suffered another concussion "he would die."

"And so did he stop playing? No," the 76-year-old widow said. "They made him a stronger helmet."

Liz Cross said she wanted to remember the joy their young grandson brought Irv over his final years and not dwell on how she had to watch the man she loved slip away.

"He was just a wonderful man," she said, "and this disease changed his life."