Buffalo placed Spector (calf) on injured reserve Saturday, Chris Jenkins of the team's official site reports.
Spector landed on the injury report Friday and logged a limited practice that day due to a calf injury. It appears that the issue is somewhat serious given that the linebacker has been placed on IR one day later. Spector's role has fluctuated this season -- for example, he logged every one of the the Bills' defensive snaps in Week 8 versus Seattle due to Terrel Bernard being sidelined but played exclusively on special teams one week later against Miami upon Bernard's return.