Jackson was carted off the field during Saturday's mock game with an apparent head injury, Bob Condotta of The Seattle Times reports.
The Seahawks have re-signed Jackson, Bob Condotta of The Seattle Times reports.
Jackson was cut by the Seahawks on Sunday, Aaron J. Fentress of The Oregonian reports.
Jackson officially signed his contract tender Tuesday, Ben Arthur of SeattlePI.com reports.
Jackson finished with 20 tackles over 15 regular-season games.
Jackson made three tackles and a sack in Sunday's 28-26 win over the Steelers.
Jackson signed his exclusive-rights free agent tender with the Seahawks on Monday, Josh Boyle of team's official site reports.
Jackson agreed to a contract with the Seahawks on Tuesday, Bob Condotta of The Seattle Times reports.
Jackson made four tackles (two solo) in Thursday's 19-17 preseason loss to the Colts.
Jackson was promoted to the Seahawks 53-man roster Saturday.