The presumed starter in the middle, DeAndre Levy, had departed during the first series with a strained groin. A knee injury had already felled backup Jordon Dizon earlier this month, leaving the Lions to use veteran Vinny Ciurciu at the position.
Ciurciu has been a special-teams player throughout his career and should be considered only the shortest of short-term solutions. Of all the areas the Lions will be scouring the waiver wire for this week, I would have to imagine that linebacker depth is at the top. Levy's summer-long inability to stay on the field -- he missed most of training camp with a back injury -- adds some urgency to the situation.
The Lions, in fact, began to address it Monday morning. According to the NFL Network, they plan to sign free-agent linebacker Rocky Boiman. I'm not sure if Boiman can address the Lions' issues at middle linebacker; he was mostly a special-teams player when he was in Tennessee with current Lions coach Jim Schwartz from 2002-05. But it's clear the Lions know they are far from settled at the position.