The number one backup defensive end will be former Cleveland Brown Keith McKenzie. Last year before McKenzie's injury he had 3 sacks with Cleveland, and the three years previous he posted eight sacks seasons.
After that, the Bears also have pass-rushing specialists Karon Riley, and rookie Alex Brown. Both of these guys were dominant college pass rushers who will continue to learn how to reach the quarterback at the NFL level.
On the inside, the Bears have added depth with Christian Peter, though he will not see major playing time behind one of the best DT combos in football. Christian can add some versatility at the position, while giving either of the big men a break without too much drop-off in play.
Many NFL followers believe that games are won and lost in the trenches. The unit should head a defense, which has the job this season of slowing down running backs including Ahman Green, Marshall Faulk, Ricky Williams, and Curtis Martin.