Seau, who will turn 40 next month, didn't go to a training camp and hasn't played a down this year. But the old warrior was good enough to appear in every game for the Patriots during their 18-1 campaign a year ago.
The reason for Seau's return could be for a spiritual kick in the pants for a team that needs to close out its final four games with authority as much as it might be for any on-field contributions he can deliver.
The Patriots haven't won consecutive games since October and haven't put together more than two victories in a row all season.
Jerod Mayo has taken Seau's place and almost certainly will be the defensive rookie of the year, but Boston Globe reporter Mike Reiss speculates inside linebacker Tedy Bruschi's knee injury could be serious enough to require reinforcements.
Reiss reports that during pregame warm-ups for Sunday's 33-10 loss to the Pittsburgh Steelers, "Bruschi was worked out by members of the team's medical and training staff on the field, which appeared to be an indication that his knee injury was serious enough to potentially keep him out of action."
Sports Illustrated's Jim Trotter broke the Seau story, citing an unnamed member of the Junior Seau Foundation:
New England coaches left open the door for Seau, 40, to return at the start of the season, but the sides could not come to terms on a new contract after Seau had offseason shoulder surgery. Seau has spent the past three months exploring business ventures and surfing in San Diego. But he always keeps himself in tremendous shape and as recently as Tuesday night at a foundation event appeared physically capable of suiting up again.