To improve their offense, the Cardinals imported talent via trade and free agency. Their defense needed just as much work, yet the Cardinals are relying upon returning players producing more than last season.
The Cardinals have gone through the preseason with the same starting front seven as last season. That group could not put pressure on the quarterback, nor stop the run, and the Cardinals finished ranked 29th overall and 30th against the run.
To show improvement, they need marquee players. Strong safety Adrian Wilson had a poor season. End Calais Campbell's production dropped over the previous season. And outside linebacker Joey Porter, a free-agent signing in 2010, had just five sacks, despite playing the entire season.
The biggest change on defense is coordinator Ray Horton. He's saddled with some of the same challenges as his predecessors, who were fired.
Horton must figure out a way to bring pressure without having a premier rusher.
Porter has played well this preseason, but at 34, he's no longer good for double-digit sacks. His backup, O'Brien Schofield, has pass-rush ability but is short on experience.
He contributed as a rookie last season and has struggled this preseason.
Horton's solution may come through creative schemes. In preseason, he has called several zone blitzes with end Darnell Dockett dropping into coverage.
Inside linebacker Stewart Bradley, a free-agent signing, is rushing the passer on third down. He's part of a nickel package that includes two down linemen, four linebackers and five defensive backs.
If Horton's pressure schemes are going to work, the Cardinals' secondary has to hold up. The team is deep at cornerback, although it doesn't have a proven elite player.
Starter Greg Toler suffered a sprained left knee last weekend and will miss the entire season. That might mean a starting spot for Patrick Peterson, the fifth overall pick in the draft.
It's questionable, too, if Wilson will return in time for the season opener. He's trying to play with a torn biceps tendon and returned to limited work in practice last week.
Overall, it's hard to judge the Cardinals' defense this preseason.
Horton's focus has been on Carolina, the opponent in the season opener, and he's called games accordingly.
Horton also is in the midst of learning his players' strengths and weaknesses, a process that's going to take most of the season.
"We're not going to show everything in preseason that we can do to bring pressure," coach Ken Whisenhunt said.
It's impossible to judge this defense over the preseason. Horton has installed a scheme similar to the Steelers' and that's a process that doesn't happen overnight.
Against Green Bay in game two, the Cardinals were able to win some one-on-one matchups and put pressure on Aaron Rodgers. That didn't happen against the Chargers and Philip Rivers.
What helps this defense is the schedule in the first month. The Cardinals open against Carolina, then follow with the Redskins, Seahawks and Giants.
There is time for this defense to grow, but then the Cardinals have been waiting a few years for that to happen.