This is the one facet of this match-up where the Cardinals hold an advantage. And it's a pretty substantial one.
Keenan McCardell was once considered an elite receiver, but has only managed 33 receptions for 398 yards this season. On the other side, Eric Parker is sure-handed, but not explosive or dangerous, and has only slightly outperformed McCardell this season (43 receptions, 597 yards). For both receivers, that's 76 receptions for 995 yards, which is an off year for either Larry Fitzgerald or Anquan Boldin.
Whether or not Eric Green or David Macklin start opposite Antrel Rolle, it shouldn't make any difference. Since San Diego operates primarily out of a two receiver, two back, one tight end set, the cornerbacks shouldn't have any difficulty locking down on their man and preventing him from breaking the game open with a big play.
The man they need to watch is tight end Antonio Gates (868 receiving yards, 8 touchdowns) and his ability to match-up against pretty much anyone in the league. He's too fast to be covered by a linebacker, but too big to be covered by a safety or a cornerback. This is why Adrian Wilson needs to shadow Gates the entire game. With some help by Orlando Huff or Karlos Dansby (depending on where the Chargers line Gates up) jamming him at the line of scrimmage, this should slow him down enough so that the defensive line (and all the blitzing linebackers - see below) have time to pressure Philip Rivers into dumping the ball off to fullback Lorenzo Neal or Tomlinson.
Gates is the most potent weapon the Chargers have on offense. He needs to be stopped in order for the Cardinals to be successful. However, Gates is really the least of their worries from a game planning perspective.
It has been an up-and-down year to say the least for Arizona's defensive line. They did a fantastic job of shutting down Thomas Jones and Cedric Benson in the Chicago game, gave up only a long screen pass to Larry Johnson in the Kansas City game, and kept Shaun Alexander pretty well bottled up in the last game against the Seahawks. However, they've also gotten gashed for huge rushing games, the most embarrassing of which was the meltdown against Green Bay.
In order to win this game, they need to stop LaDainian Tomlinson, especially in the red zone. While he gets more opportunities in the red zone than any other back in the NFL, Tomlinson also makes the most of the opportunities he gets. If the Cardinals are able to dig in, come up with critical stops on first and second down (particularly in goal-to-go situations), then that puts the game in the hands of Philip Rivers, who has struggled as of late. If the Cardinals can force the Chargers into kicking field goals instead of scoring touchdowns, they'll be way ahead of the rest of the league.
Overall, whether defending the run or the pass, Kendrick Clancy and Darnell Dockett need to clog up the middle of the line and Chike Okeafor and Antonio Smith need to seal off the edges. They need to sacrifice themselves and tie up blockers in order to create lanes (both in the run game and the passing game) for the linebackers to flow through. Against Chicago, where Arizona's defense was similarly overmatched (great offensive line, great running back, young, inexperienced quarterback), Clancy Pendergast brought out every blitz in his arsenal and was able to contain Chicago's running game and force Rex Grossman into 6 turnovers.
The front seven needs to have a game like it did against the Bears to stand a chance on Sunday.
While the defensive line simply needs to stand up at the point of attack, the linebackers need to attack the lanes created and punish whoever has the ball. Tomlinson and the Chargers offense in general aren't known for being tough, physical players. If Arizona's front seven is able to take the fight to San Diego, they should have success.
Gerald Hayes will be primarily used shooting gaps in the run game. The one man Hayes needs to watch out for is Lorenzo Neal, who is one of the best, if not the best lead blocking fullbacks in the business. He has been clearing the way for Tomlinson for a long time. Hayes needs to either win the battle at the point of attack, or clog the hole long enough for Dansby or Huff to get to Tomlinson in time.
With everyone crowding the line of scrimmage, healthy doses of blitzes, and the front seven (front eight, if you count Robert Griffith, who should be playing close to the line) committed to shutting down Tomlinson, there is the potential for Tomlinson and Rivers to hit some huge plays in this game. The Cardinals need to suffocate the run game and force Rivers to beat them. In order to do that successfully, the linebackers need to step up, fill their gap responsibilities with authority, and tackle Tomlinson when they get a shot at him. With the way they'll be set up, Tomlinson will gain a lot of yards if he can make the first man miss.
The Cardinals, basically, need to take a look at the film from their game against Chicago. I can guarantee you that the Chargers are looking at that right now. They need to crowd the line of scrimmage, play aggressive, but smart defense, and rush Rivers like crazy. Hopefully, he makes a mistake. He's only thrown 8 interceptions all year, but Grossman was pretty good at protecting the football before the Cardinals dismantled him on Monday Night Football.
San Diego is simply a better team. They have more talent on defense. They have more talent on offense. They're 13-2. The Cardinals have nothing to play for but pride, while the Chargers need to win to secure homefield advantage throughout the playoffs.
So, when you've got nothing, you've got nothing to lose. Arizona needs to blitz, blitz, and blitz some more in an attempt to create some negative plays and turnovers. The only way they're going to win this game is if they're able to force more turnovers than they commit. They're not likely to sack Rivers too much, as he's playing behind an exceptional offensive line and makes quick decisions. What they can do, however, is force him to throw the ball too early and possibly errantly, into the waiting hands of a Cardinals defender.
Blitz the run, blitz the pass, make sure you tackle well, and make sure Rolle, Green (or Macklin), and Wilson cover their man. It's going to take a nearly perfect effort to stop this offense.
Let's see if the Red Birds have it in them.