Seau became the eighth member of that Super Bowl team to die before the age of 45.
Causes of death include a one-car accident, a plane crash, lightning, a drug overdose, three heart-related ailments -- and Seau's self-inflicted gunshot wound.
"I am a common-sense guy," Jefferson told the Detroit News. "I am not the smartest guy but I've got a lot of common sense. But you sit back and watch all this happen, common sense can't make sense out of this. The numbers are too great. It's scary."
Seau's death, ruled a suicide, floored Jefferson. Soon after hearing the news, he received a call from a friend in San Diego: "He said, 'I just called to check on you, to make sure you are all right,' " Jefferson said. "'Look, I really think your team is jinxed. Be careful.' And he hung up.
"I don't usually worry about jinx stuff, but I know this isn't normal. ... We're talking about eight players dead in 18 years. Me and Sam (Gash, running backs coach) have talked about this and we're like, 'If we can just make it to 45, man.' "
Jefferson, 43, doesn't want to think this way. His memories of that tight-knit Chargers team remain special, and the deaths of former teammates haunt him still.
"I think back to that team and people are saying that team was jinxed? I remember that team being like a family," Jefferson said. "That team was blessed, big-time."