Tuesday's announcement was made by Versus, the television network on which Seau has a show. The Patriots have not announced the signing, although the team said he had a physical.
Seau is a 12-time Pro Bowl player. He came out of retirement last year to play the final four games with the Patriots after playing 27 games with them in 2006 and 2007.
Versus said the show, "Sports Jobs with Junior Seau," will continue as scheduled.