Seau's ex-wife, Gina, told The Associated Press that while Seau suffered concussions during his playing career, she had no idea if they somehow contributed to his death.

Mitchell said he didn't know where the brain was being sent and that the family's decision regarding Seau's brain was a result of wanting "to help other individuals down the road."

He said the family was not speculating as to whether concussions were a factor in Seau's suicide.

Garrett Webster, the administrator and player liaison for the Brain Injury Research Institute, which studies the impact of concussions, said his group has requested the family donate the brain but hasn't heard back.

"I don't want this to sound too crass, but we've sort of made our pitch," said Webster, the son of the late Hall of Fame center Mike Webster of the Pittsburgh Steelers. "We hope the family choses us, but the important thing is somebody's going to get it and it's going to get looked into. Junior Seau was a wonderful man and we're all aware of his work with charities. I wish it never happened. The important thing is, in some way, this will continue his legacy on giving back to the community and helping people."

Bennet Omalu, co-founder of the Brain Injury Research Institute and a forensic pathologist who first identified chronic brain damage as a factor in the deaths of some NFL players, flew to San Diego on Thursday to participate in the autopsy of Seau, two sources with knowledge of the case told ESPN's Mark Fainaru-Wada and Steve Fainaru.

Omalu assisted in the autopsy conducted by the San Diego County medical examiner because of his experience with NFL players and brain injuries, the sources said.

Mitchell said he never heard Seau complain about dizziness or headaches.

"With Junior, that would be so outside of his nature because he had an amazing threshold for pain," Mitchell said.

Family members and friends have said they weren't aware of any issues that may have led to Seau's suicide. Police said no suicide note was found.

"This is not anything I thought he would ever do," former Chargers safety Miles McPherson said.

Oceanside police released the 911 call from Seau's home one day after the San Diego County medical examiner's office ruled the death a suicide.

The call captures the voice of a woman who is horrified to find the former NFL linebacker in a spare bedroom with a gunshot wound to the chest.

"My God, my boyfriend shot himself! Oh my God!" the eight-minute call begins.

The woman, who identifies herself as Megan, said she was returning to the home Wednesday morning from a one-hour visit to the gym.

The caller is nearly hysterical and breathing heavily during much of the call as emergency workers guide her through life-saving measures that failed.

"Where is the gun?" the dispatcher asks.

"It's next to him in the bed," she answers.

"What is your boyfriend's name?"

"Junior Seau," she says.

The dispatcher asks where he was shot.

"I can't tell, ma'am. It looks like in the heart," she said.

She told the dispatcher that he did not have a pulse and that his chest was not moving.

"I just came home from the gym, and he's in our spare bedroom, and he shot himself, and it looks like he shot himself in the chest," she says after the dispatcher transferred the call to the fire department.

Nearly five minutes into the call, she goes to the door to allow rescue workers in. She explains again what happened and then begins to sob.

The woman's last name is unintelligible on the recording. Lt. Leonard Mata, a spokesman for Oceanside police, said police aren't releasing the woman's name.

Seau's family and hundreds of people held an impromptu memorial Thursday night outside his Oceanside, Calif., home near San Diego.

Seau, 43, played his first 13 seasons with the Chargers before moving on to the Miami Dolphins and 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 named All-Pro six times.

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.

Omalu's involvement may help determine whether the future Hall of Famer's suicide could be related to the growing link between football and concussions.

Omalu, the chief medical officer for San Joaquin County (Calif.), is credited with identifying chronic traumatic encephalopathy, or CTE, a neurological disorder stemming from repeated head trauma, in several deceased NFL players. CTE can lead to erratic behavior also associated with dementia and Alzheimer's disease.