The Seahawks placed Young (knee) on injured reserve Saturday, John Boyle of the team's official site reports.
Young was on IR for the first five games of the regular season due to a knee injury. He returned for Week 6 against the 49ers, but he aggravated the issue in that contest and was forced to sit for the following two games. The injury is severe enough to warrant a second stint on the IR, and Young will be forced to sit for at least the next four regular-season games. The earliest he can return will be Week 14 against the Cardinals on Sunday, Dec. 8.