This one's pretty easy. Arizona's wide receivers match up well against every secondary in the league in terms of size, speed, quickness, talent, and strength. Aside from Troy Walters, every receiver on the roster is at least 6'1", 210, or considerably bigger than the average NFL cornerback. And, as every coach from High School to the pros will tell you, you take the guys that can't catch and have average footwork and you put them on defense.
Marcus Trufant is by far the most skilled player in the Seattle secondary. But even he matches up poorly against Larry Fitzgerald and Anquan Boldin in one-on-one situations. Trufant's battery mate Kelly Herndon has some skills but is the #2 cornerback for a reason. Michael Boulware is a promising young playmaker but is still young, slightly raw, and a converted linebacker. Free safety Ken Hamlin is returning after being placed on injured reserve after an altercation in a night club. How he responds to prolonged exposure to a violent sport such as football remains to be seen.
In a schoolyard game, the trio of Boldin, Fitzgerald, and Bryant would absolutely demolish Trufant, Herndon, and rookie Kelly Jennings. However, since the Seahawks do not need to count to "five Mississippi" before they pressure Kurt Warner (and thus give the big receivers time to separate), the game figures to not boil down to a game of pitch-and-catch in Paul Allen's back yard.
Here we have what could possibly be a greater mismatch. Seattle's front seven, with its underrated defensive line of Grant Wistrom, Rocky Bernard, Chuck Darby, and Bryce Fisher, do an exceptional job of holding at the point of attack in the run game and collapsing the pocket in the passing game. While there are a number of talented players on this line (including the two guys they rotate in to keep Darby and Bernard fresh), the front seven keys off of its exceptional linebackers. Lofa Tatupu is the center of the unit and covers a lot of ground, from the secondary to the backfield to the quarterback. New addition Julian Peterson is a versatile former Pro Bowler that can play the run, cover tight ends and backs, and rush the passer. If second year standout LeRoy Hill is once again inactive for Seattle, it gives the Cardinals a better chance to compete.
The key to this game for Arizona's offense will be the offensive line's ability to get Edgerrin James past the front seven and into the secondary and their ability to protect Warner long enough for him to take advantage of the giant match-up advantage of his receivers vs. Seattle's secondary.
Or, more accurately, Edgerrin James. James excels at running the stretch and slant plays. Unfortunately, Seattle is too fast, too talented, too smart, and, frankly, too much better than Arizona's offensive line for the Cardinals to be successful running the slant and stretch out of a one back look.
If the Cardinals do not have early success running the ball and fail to convert in 3rd and long situations, Seattle's exceptionally talented offense and highly caffeinated, noisy fans will take over the game and build an early, eventually insurmountable lead. Once the Seahawks defense can focus solely on rushing the passer (a lot of people forget that they led the NFL with 50 sacks last year), a comeback will prove to be too daunting a task to accomplish.
This is why Arizona must gain an early lead, take the crowd out of the game, and begin to dictate tempo as the game wears on. They can accomplish this through superior game planning and discipline.
The Cardinals need to play to their strengths in the early going. They need to come out of the gate throwing in an attempt to back Seattle's front seven off the line of scrimmage. With quick timing passes to the receivers (especially Leonard Pope and Troy Walters, who should find plenty of space to operate in the middle of the field), screens, and draw plays, they'll be able to take some of the fury out of Seattle's pursuit. From there, with more room to operate, they should have more success running the slant and stretch plays that James prefers, since the defense will be less likely to be aggressive and attacking, preferring to take a more tentative approach. And, if the Seahawks begin to crowd the line of scrimmage, coach Green and Kurt Warner are more than able to dial up a few deep passes, especially off of play-action.
Where Seattle's defense is vulnerable is in their tendency to over-pursue and be too aggressive in their quest to tackle the ball carrier. The best way to take advantage of this is to run cut-backs and counters against the flow of the play. The Seahawks will crowd the area where the play was headed, while James will follow the pulling guard to where the play is going. Watch the Super Bowl and see if you notice that the 75-yard touchdown run Willie Parker had was a counter play.
From the base formation, they need to motion either Pope (in a three wide receiver set) or Walters (in a four wide receiver set) into the backfield as an H-Back, settling to either the left or the right side in front of James. At the snap, Walters or Pope and James need to stay at home and either block (in the case of a blitz) or separate from the line of scrimmage in order to give Warner a safety valve.
In the event of a running play, the tackles need to kick out and push their man to the outside, thus creating a wider lane of pursuit to the ball carrier for Peterson and Hill (or Hill's replacement). Stepanovich's success in this area is crucial, since he will be responsible for beating Bernard or Darby to the point of attack and preserving the cut-back lane. Pope and Walters are responsible for punishing whoever they encounter as they lead James through the hole. Hopefully, they'll encounter either Hamlin or Boulware, since encountering Tatupu would probably result in a losing battle and mean that the pulling guard was unable to eliminate Tatupu from the play because Stepanovich failed to win his battle. The Cardinals will need to alternate which side of Walters or Pope they run to throughout the game, since it will be easy for Seattle to eventually diagnose the play if Arizona always runs to the strong or weak side.
By running counters, misdirection, and the base offense out of a single formation, the Cardinals will create confusion in a Seahawks defense that is accustomed to a react-and-attack style of play. That moment's hesitation will buy Warner the time to take advantage of the one match-up where Arizona holds a decided advantage and may be the difference in this game while only possibly sacrificing Pope and Walters, who don't figure to play prominent roles in the offense this year anyway.
Above all, they need to stay disciplined (many offensive lines that are far superior to Arizona's have committed multiple false start penalties at Qwest Field), focused, and cognizant of the fact that they have nothing to lose. After all, if the Cardinals do lose this game, it was expected. If they somehow manage to emerge victorious, people around the league will begin to take notice of them, seeing as how they felled the mighty 800 pound gorilla.