Los Angeles (CNN) -- Former NFL linebacker Junior Seau sent text messages to his ex-wife and their three children "expressing love for each one of them," hours before apparently taking his own life, his pastor told CNN on Thursday.
"They said simply 'I love you.' " pastor Shawn Mitchell said. "They actually responded back to him with 'Love you too, Dad.' "
The coroner's finding on the "cause and manner" of Seau's death could be released Thursday afternoon, but it may be weeks or months before investigators conclude what led up to what they suspect was a suicide.
Seau's girlfriend found him unconscious and suffering an apparent self-inflicted gunshot wound to his chest in a bedroom of his Oceanside, California, home Wednesday morning, police said. The 43-year-old was pronounced dead at the scene after paramedics were unable to revive him.
The family is expected to decide on funeral arrangements later Thursday, with services most likely to be set for for May 12 or 13, Mitchell said.
The San Diego County Medical Examiner's Office, which is conducting Seau's autopsy Thursday, said the case is being investigated as a suicide. A handgun was found near Seau's body.
The medical examiner should issue a death certificate Thursday afternoon stating the cause and manner of death, county spokeswoman Sarah Gordon said. But toxicology results and the narrative that could reveal contributing factors in the death may take two weeks or more to complete, she added.
The possible suicide of a veteran NFL player raised questions about the condition of Seau's brain and if repeated hits to his head over his 20-year pro career could be a contributing factor.
While the brains of several other players have undergone post-mortem study on the effects of football-related concussions, the medical examiner's office could not immediately say what would be done with Seau's brain, Gordon said.
Mitchell, who is the team chaplain for the San Diego Chargers, said he has received calls from brain researchers asking to be able to perform their own studies on Seau's brain.
The suicide of former Chicago Bears safety David Duerson, who shot himself in the chest in February 2011, raises concern about Seau's death, Mitchell said.
Duerson left behind a note requesting that his brain be studied for evidence of a disease striking football players. Researchers at Boston University's School of Medicine Center for the Study of Traumatic Encephalopathy reported that Duerson's brain tissue showed "moderately advanced" evidence of chronic traumatic encephalopathy, a dementia-like brain disease afflicting athletes exposed to repeated brain trauma.
Seau played "the most havoc-ridden position on the team," he said. "He suffered many concussions, so there is a strong sense" that it could have played a role in his death.
"Him taking the shot to the chest makes sense that he would want his head examined," Mitchell said.
Seau was drafted into the NFL in the first round in 1990 out of the University of Southern California. He debuted with the San Diego Chargers, establishing his Hall of Fame potential as a Pro Bowl staple.
He left San Diego before the 2003 season to join the Miami Dolphins and spent parts of the last four seasons with the New England Patriots before retiring in January. Seau amassed 1,526 tackles, 56.5 sacks and 18 interceptions in his 20-season career.