"This is not anything I thought he would ever do," former San Diego Chargers safety Miles McPherson said.
Like many of Seau's friends, McPherson was still trying to comprehend the death of the former star NFL linebacker the day after his body was found inside his home in suburban Oceanside with a self-inflicted gunshot wound to the chest. The San Diego County medical examiner ruled the death a suicide on Thursday.
"Junior is a warrior. He played 20 years in the NFL as a linebacker. You have to be a warrior. Warriors conquer problems they face and they run at them," McPherson said Thursday.
McPherson, now the pastor at the Rock Church in San Diego, said that's why Seau's death is so puzzling.
Seau's ex-wife, Gina, told The Associated Press that while Seau sustained concussions during his playing career, she had no idea if they somehow contributed to his death.
McPherson also said he didn't know if concussions would have contributed to the death of Seau, who was known for his ferocious tackles followed by celebratory fist pumps.
"There is no football player — maybe a punter — that has not had multiple concussions, I would guess," McPherson said.
Longtime Chargers chaplain Shawn Mitchell said he wasn't aware of any major issues that would lead Seau to take his life, including any difficulties making the transition from the playing field to retirement. Seau played his first 13 seasons with the Chargers before moving on to the Miami Dolphins and then the New England Patriots.
He helped lead San Diego to its only Super Bowl, after the 1994 season; was voted to a Chargers-record 12 straight Pro Bowls; and was a six-time All-Pro selection.
Mitchell said many players struggle once they leave the game.
"Junior was quite the opposite," said Mitchell, the pastor at New Venture Christian Fellowship in Oceanside. "Junior was one of the few guys with face recognition and first-name recognition across the nation. I'm almost amazed when people say he was torn up and missing the limelight. Golly, for a guy not in the league, the guy was doing contracts and he had a series on TV. He was such an icon and he had three cities, San Diego, New England and Miami, which loved the guy. I haven't seen in Junior what I see in hundreds of players, and that is a sense of great loss."
For a time, Seau hosted a reality show called "Sports Jobs with Junior Seau." He also continued to run his restaurant in Mission Valley, which has been open since the mid-1990s.
"Again, I'm not trying to paint a picture of everything being rosy. Junior, just like us, had feet of clay. There was absolutely nothing out of the ordinary and I don't think he missed totally being out of game," Mitchell said.
In October 2010, Seau survived a 100-foot plunge down a seaside cliff in his SUV, hours after he was arrested for investigation of domestic violence at the Oceanside home he shared with his girlfriend. The woman had told authorities that Seau assaulted her during an argument.
There was no evidence of drugs or alcohol involved in the crash and Seau told authorities he fell asleep while driving. He sustained minor injuries.
McPherson said the only issue he was aware of was "the normal struggling with retirement issues, but nothing I thought would ever come to this."
McPherson painted a picture of what it could be like for a player of Seau's calibre once his playing career ended.
"When you grow up an athlete and you live in a world that praises you all the time as you go from high school to college, college to the pros, the decibel volume, the number of people, the frequency of praise that comes your way, increases," said McPherson, who was with the Chargers from 1982-85. "By the time you get to play 20 years in the NFL, in 12 consecutive Pro Bowls, and all that comes with that, you're living in fantasyland.
"All that one day stops. But your body, mind and heart are conditioned to such a high level of excitement, adrenaline rush, challenge, and then you're like taken off the drug, cold turkey. A lot of guys, women as well, celebrities, who live in a bubble, have a hard time living with normal life. Unless they can emotionally and spiritually handle the letdown and transition to something that will satisfy them, even though it will never bring the adrenaline rush their career did, they're somewhat at a loss."
McPherson knew the 43-year-old Seau was busy in his post-playing days. "I also know he was a very charismatic guy and the limelight that shone on him was very bright. Even though he was busy, it could never match what he had."
Seau was described as upbeat and invincible.
A few weeks ago, a smiling Seau was videotaped playing a ukulele and singing while attending the spring game at Southern California, where he starred before being drafted by the Chargers in 1990.
Mitchell said that friends of Seau's who were at his charity golf tournament a month ago said his "spirits were great."
During emotional remarks to reporters on Wednesday, Seau's mother, Luisa, said her son gave no indication of a problem when she spoke to him by phone earlier this week.
"He's joking to me, he called me a 'homegirl,'" she said.
Seau purchased his Oceanside home for $3.2 million in August 2005, near the peak of the housing boom in San Diego. Sharon Ferguson, assistant division chief in the San Diego County assessor's office, said there were no liens against his property.
If Seau was having trouble with something, he didn't let anyone know. Police said no suicide note was found.
Mitchell and McPherson wish Seau had reached out to somebody.
"I'm sorry to say, Superman is dead. All of us can appear to be super, but all of us need to reach out and find support when we're hurting," Mitchell said. "This super person, this wonderful human being, this extraordinary athlete and man, if someone so invincible like Junior could end his life this way, it should be a message to all of us all going through hurt and travails, that we all need each other. If somebody's hurting, please talk to somebody. Get help."
Further autopsy details, including results of toxicology tests, will be released in a final investigative report, which may take up to 90 days to complete.
The medical examiner's office said it was awaiting a decision by the family on whether to turn over Seau's brain to unidentified outside researchers for study.
Boston University's Center for the Study of Traumatic Encephalopathy has analyzed the brains of dozens of former athletes, including that of former Chicago player Dave Duerson, who shot himself in the chest last year.
While saying it was saddened by Seau's death, centre officials would not say if they have reached out to the Seau family or would be interested in studying his brain.
Duerson's family has filed a wrongful death suit against the NFL, claiming the league didn't do enough to prevent or treat concussions that severely damaged Duerson's brain before he died in February 2011.
Former Atlanta Falcons safety Ray Easterling, who had joined in a concussion-related lawsuit against the league — one of dozens filed in the last year — shot himself last month at age 62. His wife has said he suffered from depression and dementia after taking years of hits.
Seau is not known to have been a plaintiff in the concussion litigation.
AP Sports Writer Jimmy Golen in Boston contributed to this report.