Allen Pinkett

When USC visits Notre Dame on Saturday things will be far from what most figured on in the preseason when they circled the date of this annual clash of intense rivals.

Notre Dame is 1-6 and this week the Irish changed their starting quarterback, going to junior Evan Sharpley and going away from highly-touted freshman Jimmy Clausen, who has been inefficient and gotten banged up since being tabbed the No. 1 quarterback beginning with the second game of the season against Penn State.

USC, thought by many to be a virtual lock to play in the BCS title game, is stumbling, beaten in a shocking upset two weeks ago by 40-point underdog Stanford, and winning ugly last week against Arizona.

The biggest keys for Notre Dame in its upset bid will be stopping the run, pressuring the quarterback, and creating turnovers.

For USC to come away with a win the top priority is to control the line of scrimmage because the Trojans have the ability to overwhelm opponents with their talent -- as long as they don't make mistakes like they did against the Cardinal when they committed five turnovers.

Making the right call at quarterback
Since Notre Dame head coach Charlie Weis has previously stated that Sharpley ran the offense the best, the junior could have been tabbed to open the season as the starting quarterback. The reason that didn't happen is that in practice Sharpley is not nearly as accurate as he is in games and that concerns Weis.

Clausen may have more natural talent than Sharpley, but the Irish offense has performed better with Sharpley as quarterback. He has a better grasp on the offense and has shown a propensity to make plays. It's not just executing the play that is called, it's what the quarterback can add to that play that could turn it into a big gain. That's something Sharpley has hinted he is capable of in his relief stints against Purdue and Boston College.

Now he gets his chance against USC, no easy undertaking but pressure is what a quarterback brings on himself. Sharpley should not look at this opportunity as a pressure-packed situation but rather view it as a challenge that all players who want to be the starting quarterback at Notre Dame would hope would come their way. Sharpley should welcome the opportunity to play against a top-flight opponent in USC.

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With Sharpley the Irish have a better shot at stretching the field. That was evident in the junior's play against Boston College. Sharpley has a knack for when to take a chance and when not to. It can't be denied that the Irish offense was anemic under Clausen. The freshman may have been cautious to a fault. Expect Sharpley to be a bit more daring in his play.

On a team heavy in youth and inexperience as Notre Dame is, it's a sense of comfort to have someone at quarterback who has been in the program for a few years, even if until this season he was nothing more than an understudy to Brady Quinn. The move to Sharpley can't be questioned.

Trojans far from one dimensional
The USC attack can strike on the ground or through the air. The Irish have seen the numbers for the Trojans' running game -- an average pick up of over five yards a carry and about 200 yards rushed for per game. To take on such a solid rushing attack, the Irish defense must do well on first down. Notre Dame must prove tough to run against on first down, thereby creating long yardage situations on second and possibly third down, which will force USC to throw more and get away from the impressive balance it has on offense.

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But it will take a huge step forward in the play of Notre Dame defenders to prevent USC from moving the ball on the ground. The Irish have allowed over 1,300 yards rushing, surrendering an average of 4.2 yards per carry and over 186 yards per game.

Why such vulnerability to the run?

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Well, it could at least in part be because Notre Dame switched this season from a 4-3 defense to a 3-4. But it's been behind the 8-ball in this transformation because it doesn't yet have the personnel ready to best execute a 3-4. What Notre Dame might do against USC is play a little more 4-3 than usual or play more nickel. The objective in going to either of these options is to rush four down linemen in an attempt to get better penetration than is occurring with the 3-4.

The main reason the Irish went to the 3-4 was to improve their pass defense. And that's happened. But the USC air show, which throws for about 230 yards a game, will be looking to out-perform the Irish secondary. At quarterback for USC will be either John David Booty, who broke the middle finger on his throwing hand in the Trojans shocking loss to Stanford, or third-year sophomore Mark Sanchez, who made his first start in last week's 20-13 win over Arizona. With either one behind center USC coach Pete Carroll won't be shy about putting the ball in the air.