Chargers-Cardinals: Two Different Approaches
Each team prepared for the Chargers' 34-31 victory differently, which led to both the Cardinals quick start and the Chargers calculated response. Arizona, who had more new faces on the field than an elementary school registration day, needed to prepare like a regular season matchup. The Chargers wanted to keep their veterans injury-free, get out of the heat, and look at only a few specifics.
Arizona did not stay in base defense long, dialing up blitz packages and incorporating defensive line stunts with the first series. It worked. They wreaked havoc in the backfield, stifling the run and forcing Rivers to pass too soon.
On offense, the Cardinals mixed the run inside and out, using play action and draws, and were always willing to go over the top in the passing game. Their aggression was tangible. They saw Fitzgerald in single coverage and knew it meant he was one good move from scoring a TD. Arizona came into the game without an identity and they needed to have success. They got both. 

Chargers Offense vs. Arizona Defense
Most fans were probably wondering when the Chargers would put all five offensive lineman on the field—sure looked like they had just three in the first quarter. There was a lot of Cardinal Red in the Bolts backfield and the Chargers’ running game was non-existent. Philip Rivers didn’t complete his drop steps before needing to get rid of the ball and couldn’t step into a throw until the 2nd quarter.
The results were clear: 19 yards rushing on 9 carries, three tipped passes and an interception returned for a TD after fifteen minutes of play.
Norv Turner was seen scanning the crowd for Chargers fans with jerseys on, asking if they would play center, guard or tackle.  
Yes, you saw that right: on one play, Arizona defensive lineman David Carter beat Chargers guard Tyrone Green so badly while getting to the RB he should have been given two tackles.
And yes, it definitely seems San Diego hasn’t figured out Special Teams plays can result in points on the scoreboard. Their coverage against Arizona was last year’s model, which seems to deliberately ignore how a two-man wedge and a single cutback can break open the line. Arizona didn’t even have to be creative when shredding San Diego’s unit.

Chargers Defense vs. Arizona Offense
One thing is certain: the Chargers cannot play single coverage against Larry Fitzgerald. And while you can’t blame Bob Sanders for trying to strip Fitzgerald on one play, you also can’t blame Larry for his amazing leg strength as he was able to break away from the pile for more yards. Lesson learned.
Another thing is certain: the Chargers base defense isn’t good enough to play straight up against an offense. While the Cardinals were executing designed plays, the Chargers were left in one-on-one matchups reacting to the ball from their heels.
But while the outcome wasn’t pretty, that defensive strategy was by design.
Why? San Diego had little interest in revealing blitz packages early against Arizona. They did what a lot of defenses do to start a game: begin with base coverage, watch how they’re attacked, then make adjustments.
The difference is that even in a regular season matchup the Chargers wouldn’t allow a single cornerback to cover Larry Fitzgerald. And no blitz except for the four down linemen? Kolb had plenty of time to find his favorite receiver.  
(No offense to Larry Fitzgerald. There’s no question his athletic ability was more than the Chargers were ready for even if they had planned for him. But, if you look closely at the video, you can see him drooling at the line of scrimmage, trying to wink at Kolb and occasionally shouting, “HEY! I’M OPEN!”)

Don’t lose faith just yet. You’re right, the first quarter was ugly. But it was probably good for the Chargers. They played so well at Dallas they needed a reminder they can’t get by on ability alone. It will take a well-executed plan, too.
Fortunately, Turner wasn’t about to throw his boys to the birds entirely.
The second quarter was a complete turnaround. A few screen passes slowed down Arizona’s pressure and the offensive line began using protection schemes against the stunts. San Diego’s offense also decided it was time to exploit the obvious matchup advantages of Jackson, Floyd and Gates vs. Arizona’s young secondary. With Rodgers-Cromartie no longer locking down wideouts, the Chargers dropped the hammer on the talented but inexperienced Patrick Peterson.
On defense, the Chargers sent more blitzes, made Kolb move around/escape the pocket, and kept pressure in the backfield. Corey Liuget showed off an NFL motor, and was rewarded for his intensity on two plays because of his upfield push and his “Too Liuget To Quit” hustle. The secondary rolled over backside coverage to help keep Larry Fitzgerald in check and Kolb was forced to go to Early Doucet and Todd Heap, lesser options in the Cardinal offense.
Feel free to continue complaining about the running game and Ryan Mathews. But make sure you blame the offensive line, some terrible play-calling, and the fact that Mathews’ blocking still doesn’t involve opening his eyes, making it a near-certainty the Chargers will not pass with him in the game. Sad truth: if an NFL defense knows when you’re going to run they will stop you.
And remember that the Chargers use screens and passes in the flats like a run to the outside (which they rarely use). It’s a good strategy because it means defenders come at the QB first, who then tosses to the back, as opposed to defenders seeing a handoff and immediately beginning pursuit. It can be an advantage as long as it’s executed well. And it’s another reason Tolbert gets more playing time than Mathews: the back must be able to pass block so short tosses can be disguised and effectively mixed with other passing plays.
If this game had been a regular season matchup the Chargers would have won handily. Arizona has some talent, but they’re clearly still learning. And when the Chargers wanted to turn on their offense or shut down the opposition, they were capable. The lingering question for San Diego involves special teams, as that unit effectively gave away their playoff spot last year. 

Other News and Notes
The second half of the game was a series of auditions by players trying to make their teams, as well as some situational game-planning. DL Barnes and LB Gamble were both solid again and San Diego Union-Tribune beat reporter Kevin Acee thinks they are likely to make the team.
WR Bryan Walters has been Jekyll and Hyde so far. He hangs onto the ball while sandwiched between two defenders on one play, and then the next pass slips through his fingers in light coverage. He has a great upfield block to extend a play for the runner, showing great awareness. Then he muffs a punt.
Walters and Goodman probably will stick as the 5th and 6th WRs, due in no small part to their (potential) special teams contributions. But it’s possible only one of them makes it—something to watch in the final preseason game.