Indispensable player: USC

See your team in your mind's eye -- 24 starters, including specialists.

If you could put an absolute halo of safety -- perhaps a girdle of indestructibility -- around just one, who would it be?

We're rating each team's most indispensable player. And when the choice is too obvious -- say, Stanford -- we'll try to offer a second choice.

Up next: USC

QB Matt Barkley

Yes, this is obvious. But it's also absolutely accurate, and no other Trojan even comes close to Barkley in importance. For one, Barkley is a two-year starter and a future first-round NFL draft pick who will be in his second year working with coach -- and playcaller -- Lane Kiffin after throwing 26 touchdown passes last year and ranking third in the Pac-10 in passing efficiency. Just about everyone expects Barkley to make a significant step forward in 2011, with his considerable talent finally meeting the hype that has surrounded him since he started as a true freshman and had coach Pete Carroll gushing like a school girl considering the merits of Justin Bieber. But it's not just about Barkley. If Aaron Corp or Mitch Mustain were still around, we might even tap someone else -- defensive end Nick Perry or offensive tackle Matt Kalil? -- as the most indispensable Trojan. But Barkley's backup is redshirt freshman Jesse Scroggins, who's a fine talent but isn't ready for prime time. Further, with a makeshift and questionable offensive line, the Trojans need an experienced quarterback who has played under pressure and understands the nuances of negotiating a pass rush. And, finally, the Trojans are going to have a young but extremely talented crew at receiver. They not only need a guy who can get them the ball, they need a guy who thoroughly knows the offense and can put them in the right place. In fact, with NCAA sanctions killing USC's postseason possibilities, Barkley's leadership skills will be nearly as important as his physical skills. USC needs someone to keep his team's spirits up, to keep them focused and to, at times, give them a kick in the pants. If Barkley goes down, it's not hyperbole to suggest the Trojans become a .500 team.