Candidates normally aren't eligible to be voted in until two years after their careers end or their deaths.
Seau, the hard-hitting, first-pumping leader of the Chargers for 13 of his 20 NFL seasons, committed suicide May 2. He grew up in suburban Oceanside and was a star at Southern California.
Denise Cooper, president of the Hall of Champions, says Seau ''was pretty special and we wanted to do this immediately.''
The Chargers retired Seau's No. 55 on Sunday.
The other inductees will be announced next week.