Seau's youngest brother, 36-year-old Tony Seau, died Thursday at a local hospital. According to reports, friends and family posted on Twitter that he had a heart attack.
Tony Seau played football as well at Palomar College in San Marcos and Eastern Washington University. But he had problems off the field. Back in 1993, he pleaded guilty to attempted murder in a gang-related attack that wounded a man. He served time at the California Youth Authority.
While at Eastern Washington in 2002, he was shot in the head during a gang-fueled argument at a party.
Junior Seau died of a self-inflicted gunshot wound in May 2012. He was 43.
The Associated Press contributed to this report.