Wes Hopkins, one of the NFL's most feared hitters when he played safety for the Eagles in the 1980s and early 1990s, died on Friday at 57, the team confirmed.

The cause of death was not made public. Mr. Hopkins, who lived in Birmingham, Ala., had been in failing health for a couple of months.

A walk-on college player at Southern Methodist University who wound up in its hall of fame, Mr. Hopkins was selected by the Eagles in the second round of the 1983 draft and started 14 games as a rookie. He had 11 interceptions combined in 1984 and 1985 and was a first-team All-Pro selection in 1985 before tearing up his left knee early in the 1986 season.

Standing at 6-foot-1 and weighing 213 pounds when he played, Mr. Hopkins missed the rest of the 1986 season and all of 1987 but returned in 1988 and won back the starting job. He retired after the 1993 season, finishing his career with 30 interceptions and 12 sacks.

"Wes Hopkins is one of the best safeties in the history of our franchise and played a major role in the team's success during his time here in Philadelphia,'' Eagles owner Jeffrey Lurie said in a statement.

Former Eagles wide receiver and current radio analyst Mike Quick was one of Mr. Hopkins' teammates.

"He was a great player and a great intimidator,'' Quick said. "Being an intimidator at that time was a real valued thing because the game was different then.

"I remember being at the Pro Bowl with [former St. Louis Cardinals wide receiver] Roy Green the year Wes hurt his knee. Roy was worried about whether Wes was going to be coming back. He kept asking me about him.

"I thought that was a heck of a compliment. I mean, here's an All-Pro wide receiver out at the Pro Bowl, and he's worried about whether he was going to have to face a guy the next season who had torn up his knee.''

Green was hardly the only NFL receiver who dreaded going across the middle during the 10 seasons Mr. Hopkins played free safety for the Eagles.

"People speak of the big hitters that played the game, but I don't hear Wes's name enough,'' said Harvey Armstrong, a former defensive tackle, Eagles teammate and close friend of Mr. Hopkins. "I was just talking with Eric Dickerson, and he was talking about the big hitter that Wes was. He put him right up there with the top hitters who have ever played the game.''

Armstrong said he is fairly certain that Mr. Hopkins was suffering from chronic traumatic encephalopathy (CTE), a degenerative brain disease that has been found in more than 100 former NFL players whose families donated their brains for research.

"He just went into a shell, much like Andre [Waters] did," Armstrong said. "You could see some of the things he was dealing with. The depression and the anxiety and the other things that CTE causes.''

Waters, who played alongside Mr. Hopkins for nine seasons, committed suicide in 2006 at 44.

"I went to see him when he was first admitted" to the hospital, Armstrong said of Mr. Hopkins. "They didn't think he was going to make it through the week.

"But I sat there with him for two days, and you could see him getting stronger and trying to speak. A week later, his family sent me pictures of him doing rehab. He had gotten out of ICU. He was moving better. Speaking.

"Wes fought his whole life. I thought he would get through this because he's always persevered. He's always beaten the obstacles that he's faced. But it got to a point where he couldn't fight anymore.''

Former linebacker Seth Joyner, another Eagles teammate, said the recovery from the knee injury was difficult for Mr. Hopkins.

"He struggled when he came back to be as explosive as he was before the injury," Joyner said. "But he figured out how to play the game the best he could with what he had. But even with that, he still was one of the top safeties in the game. The guy just would not give up. He went through hamstring injuries and quad injuries and a million other things. And he never gave up.''

"When he got hurt," Armstrong said, "they weren't even sure he'd be able to walk again let alone play football. I was with the Colts after he got hurt. I remember him calling me and saying, 'I've got to find a way to get back on the field." And he did.

In 1989, coach Buddy Ryan tried to give Mr. Hopkins' starting free safety job to Terry Hoage. But Hoage got hurt, and Mr. Hopkins replaced him. Hoage never got his job back. A year later, Ryan selected Ben Smith in the first round of the draft with the idea that he would replace Mr. Hopkins. Smith ended up being moved to cornerback.

"You just learn not to quit,'' Mr. Hopkins said in 1990. "You learn how to overcome it. There is no quit in me. I have the confidence to know I'm one of the best. Whether somebody else knows that is something else.''

Mr. Hopkins ended up outlasting the man who had constantly tried to get rid of him. Ryan was fired after the 1990 season.

"He was well-respected among his teammates and coaches not only because of the way he played the game and what he was able to accomplish on the field but also because of the way he carried himself and the type of leader he was," Lurie of Mr. Hopkins in his statement. "He had a genuine love of the game, and that's one of the reasons he connected so well with the people of Philadelphia.''

Armstrong was in Philadelphia last week for the Colts game, and he said he was touched by how many fans were still wearing his friend's kelly green No. 48 jersey.

"I went up to the people wearing them and took pictures with them and told them about Wes and what was going on with him," Armstrong said. "I sent the pics to Wes's mom. She showed them to Wes. She said they made his day, how people still were showing love to him.''

Services for Mr. Hopkins were pending.