The Seahawks placed Forsythe on injured reserve Wednesday due to a hand injury, John Boyle of the team's official site reports.
Forsythe's move to injured reserves opens a spot on the Seahawks' active roster, which was used to claim linebacker Josh Ross off waivers. Forsythe was unable to play in Week 7 due to a hand injury, and he'll now be forced to miss at least the next four games, making Week 13 against the Jets on Dec. 1 the earliest he can return. Michael Jerrell started at right tackle in Week 7, though he could cede the job to George Fant (knee), whose 21-day practice window opened Wednesday.