Breaking news: The Cardinals have made their first move of the offseason by firing Defensive Coordinator Billy Davis who was promoted from being the Linebackers coach to the Defensive Coordinator in 2009 following the firing of Clancy Pendergast. He was routinely criticized by Cardinals fans this season for poor and predictable schemes as well as the poor play of the Defense as a whole. it often seemed like he wasn't placing the players in their best position to succeed, and the other team was taking advantage of that. Just look at all of the times Adrian Wilson was exposed in coverage when it was known that coverage is his weakness. He did have some very well called games like the ones against the Giants and Vikings in 2009, and against the Saints, Rams and Broncos in 2010, but overall the blowouts came far too often and there were still too many big plays given up by the Defense for him to stay.
As a whole, the Cardinals ranked 29th in total defense, 30th in rushing defense, 23rd in passing defense, 30th in points per game, 17th in sacks per passing attempts, and surprisingly given the struggles of the defense they were 1st in Red Zone defense.
One name to keep an eye out for is Steelers Linebackers coach Keith Butler. The Cardinals tried to get him from the Steelers after Ken Whisenhunt came here in 2007, and following the firing of Clancy Pendergast in 2009.