Top 10 performers, No. 4: Robey

We're doing a series on the Trojans' top 10 performers in 2011, ranking the team's best players based on their overall value to the team last season.

The first six players, in descending order, were T.J. McDonald, Christian Tupou, Curtis McNeal, Nick Perry, Dion Bailey and Marqise Lee. Here's No. 4 now: cornerback Nickell Robey.

He doesn't look the part, standing a listed 5-8 and 165 pounds and actually measuring in closer to 5-6 and 160. But Nickell Robey is a dogged defender for the Trojans and arguably the most important player on the USC defense.

Thinking of the top players the Trojans faced this season, four of the top 10 or so threats USC went up against were wide receivers. Notre Dame's Michael Floyd, Arizona's Juron Criner, Cal's Keenan Allen and UCLA's Nelson Rosario all fit into that category, and Robey totally shut down both Floyd and Criner.

Allen and Rosario had good games, but that's to be expected when dealing with elite threats. They will still good games on occasion, no matter the quality of the defense. It's telling, though, that Floyd, a likely first-rounder in next April's draft, couldn't get anything going against Robey, and Criner, a guy with four 100-yard games in 2011, had his second-worst game of the season.

Consider, also, that those players are seven and eight inches taller than Robey, respectively. That gives you some context to just how dominant Robey was.

And consider what USC would have had to do at the cornerback position if he weren't there. Remember the weeks between when Torin Harris got hurt and Isiah Wiley emerged as a legitimate No. 2 guy? Tony Burnett struggled mightily.

Without Robey, he would have been forced to start all year. Without Robey, USC's pass defense would have been truly terrible. It sounds crazy to say, but the short sophomore from Central Florida was the most important piece to the defensive success the Trojans did have in 2011 -- whatever success that is, of course.

And you could also make the argument that deserves to be ranked above one or two of the players we are going to rank above him in Robert Woods, Matt Barkley and Matt Kalil. If you're grading it strictly on a basis of whose absence would have caused the team the most trouble, Robey should be ahead of Woods.

Now, the question with him is if he can elevate his game to another level, as he did from Years 1 to 2. Going by the parameters of the list, he's probably going to be the second-most valuable returner to the Trojans next season, assuming Barkley doesn't return for his senior season.

Can he up his play from All-Conference caliber to All-American? It's very possible.

Check back Wednesday as we continue to count down our final three of Barkley, Woods and Kalil -- in what some may consider an unusual order. We'll also reveal a five-man honorable mention list on Friday.