Ngata, who returned to practice Friday and was officially listed as questionable, injured his right knee on Nov. 10 and missed last Sunday's game at Chicago. He hasn't missed back-to-back games since November 2009.
The only surprise inactive is wide receiver Deonte Thompson, who had played in seven straight games. He only had one catch in his past two games. With Thompson out, wide receiver Brandon Stokley is active for the first time since Week 3.