Cosgrove is a poor to fair D Coordinator (look at his ten-year record as UW - ouch). I am not confident his tinkering will amount to anything. Concerns about the D-line (inexperienced), the linebackers (slow) and the DB's (small corners, average safety's) lead me to think this Nebraska season will hinge on the Defense's ability to get it done - or not. If the offense performs and the defense struggles, I think Callahan will have to make a move at DC.