The Seahawks placed Fant on injured reserve Saturday due to a knee injury, Bob Condotta of The Seattle Times reports.
Fant sustained the knee injury in Week 1 against the Broncos, and he was unable to play in Week 2 against the Patriots. He was a limited participant in all three practice sessions this week, but he was ruled out for Sunday's game against the Dolphins. Now that he's on IR, the 32-year-old offensive lineman will be forced to sit for at least four games, and the earliest he can return is Week 7 against the Falcons on Oct. 20. Stone Forsythe will hold down the starting job at right tackle while Fant is sidelined.