The Steelers defense lost two starters Sunday-DE Travis Kirschke (calf) and ILB Lawrence Timmons (sprained ankle). The extent of the injuries is not known, but the loss of Kirschke would be a bigger blow because he already was replacing Aaron Smith, who is out for the season with a torn rotator. If Timmons can't play, Keyaron Fox, who started three games earlier this season when Timmons was injured, would be more than a capable replacement.