The move is largely precautionary, and Shiancoe was brought in in case the Seahawks run into a scenario where they need an additional tight end. There has been no signing to this point.
The New England Patriots released the nine-year veteran last week after their starters returned to the lineup following injuries.
Shiancoe has played in four games in 2012, did not start in any of them and did not record a reception. With the Minnesota Vikings in 2011, he played in 16 games, starting 14, and recorded 36 catches for 409 yards and three touchdowns.
The Seahawks' depth chart at tight end includes Zach Miller, Anthony McCoy and Evan Moore, none of whom appeared on the team's injury report leading up to Sunday's game against the Buffalo Bills. Seattle will next take on the San Francisco 49ers at the "Clink" on Sunday night in a nationally televised game.