The Seahawks placed Peterson (lower back) on the practice squad injured list Wednesday, John Boyle of the team's official site reports.
Coach Pete Carroll had an ominous tone when speaking of Peterson earlier Wednesday, saying the running back's lower back hadn't responded well to treatment, and that the team may have an update on his status soon, according to Bob Condotta of The Seattle Times. With this transaction, Peterson's campaign is over. He'll finish his 15th season with 38 carries for 98 yards and two touchdowns to go with four catches (on four targets) for eight yards in four appearances between Seattle (one) and Tennessee (three).