The Seahawks placed Haynes (toe) on injured reserve Thursday, John Boyle of the team's official site reports.
Haynes didn't practice all week and had previously been ruled out for Seattle's Week 13 contest, but he'll now be forced to miss the team's next four games after going on IR. The veteran offensive lineman had started all eight games he appeared in for the Seahawks this season, and Damien Lewis is expected to take over at left guard until Haynes is able to return to the field.