The San Diego Union-Tribune first reported last week that Seau was ready to return to the Pats for another season, and the two sides made it official Monday with a one-year contract. Financial details of the deal for the 17-year veteran were not immediately available.
Seau, 38, signed a one-year contract with New England last August, just a few days after he announced his retirement from the league.
He appeared in the first 11 games, with 10 starts, at inside linebacker in 2006. Playing principally on first and second downs, he registered 70 tackles, one sack and one pass defensed. In a Nov. 12 game against the New York Jets, he had a season-high 15 tackles. Seau, whose previous three seasons had been fairly unproductive, played well for the Patriots in his primary role as a run defender.
Seau's season ended prematurely, however, in November when he suffered a broken right forearm that landed him on injured reserve.
The injury has healed completely, and Seau has built up strength in the arm, and he let it be known that he wanted to play another season. Team officials have been discussing with Seau his possible return for a few weeks.
It is not known exactly when Seau will rejoin the Pats, who have begun the organized team activities segment of their offseason regimen, for workouts.
A first-round pick of the San Diego Chargers in the 1990 draft, Seau is viewed as a likely future Hall of Fame member.
The former Southern California star played 13 seasons with the Chargers (1990-2002) before being traded to the Miami Dolphins in 2003. He was released by Miami after three years, and then ended his brief retirement last summer to sign with New England.
In 241 games, including 237 starts, Seau has registered 1,794 career tackles, 53 sacks, 15 interceptions, 94 passes defensed, 12 forced fumbles and 17 fumble recoveries. Beyond his dozen Pro Bowl appearances, Seau was named to the all-decade team for the 1990s. In 1994, he was recognized as the league's Man of the Year for his off-field endeavors.
Len Pasquarelli is a senior writer for ESPN.com.