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The biggest surprise player on the NFL's biggest surprise team has been Kansas City Chiefs rookie cornerback Marcus Cooper. Claimed off waivers from the San Francisco 49ers in August, Cooper has stepped into a significant role on the NFL's top-ranked scoring defense.

Through the first nine games of the season, based on the way he's played, there's even good reason to add Cooper's name to the discussion of NFL's Defensive Rookie of the Year.

The Chiefs made headlines this offseason in free agency when they signed former Miami Dolphins cornerback Sean Smith and former Atlanta Falcons cornerback Dunta Robinson to multi-year deals.

It was Smith and Robinson who were supposed to pair up with Brandon Flowers to form a formidable Chiefs secondary, but it's been Cooper who's shined the brightest thus far.

Getting to Kansas City

Cooper was initially drafted out of Rutgers by the San Francisco 49ers in the seventh round. Just two picks away from being Mr. Irrelevant, the very last pick in the draft, Cooper made it all the way to final cuts for the 49ers before he was released.

Not bad for a player entering the NFL who had only played cornerback for three years in college, initially going to Rutgers as a highly touted wide receiver.

But the long-armed, 6'2", 192-pound Cooper wasn't fazed by his initial release from the 49ers via Mike Vorkunov of The Star-Ledger.

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"It was a little bit of a disappointment but I knew things happen for a reason," Cooper said. "I didn't really have to worry about the next step."

The 49ers knew there was a chance they wouldn't be able to sign Cooper back to their practice squad when they made him available, via Matt Maiocco of CSN Bay Area:

“We had some concern,” 49ers general manager Trent Baalke said recently. “Did we think there was a chance we could get him through? Yeah, we did. But we also knew . . . Any time you expose a player, you have to do with the mindset that you've lost that player."

The Chiefs played the 49ers in the preseason, so they were able to get a good look at Cooper before he was released. But he didn't exactly light up the box score in that game.

He played 26 of the 64 snaps and finished with a negative grade (-0.6), according to Pro Football Focus (subscription required).

Despite the PFF rating, the Chiefs obviously saw something in Cooper they liked, and when he became available, they jumped on the opportunity to add him to their 53-man roster.

Cooper's 6'2" frame likens his physical ability to Sean Smith, who, at 6'3" and 218 pounds, is one of the biggest cornerbacks in the NFL. Chiefs defensive coordinator Bob Sutton almost assuredly targeted Cooper in part due to his size.

Stats and Rankings

Through nine games this season, Cooper is currently ranked as the No. 2 cornerback in coverage and the No. 4 cornerback overall, according to PFF.

He's given up just 15 receptions on 39 passes thrown at him, and that completion percentage of 38.5 is tied for best in the NFL with Alterraun Verner of the Tennessee Titans.

As you can see below, Cooper is in some pretty elite company right now with how he's played through these first nine games.

PFF's top-ranked cornerbacks through nine weeks Player Team Grade Darrelle Revis Tampa Bay Buccaneers 13.8 Jason McCourty Tennessee Titans 12.1 Alterraun Verner Tennessee Titans 11.7 Marcus Cooper Kansas City Chiefs 10.5 Richard Sherman Seattle Seahawks 9.2 ProFootballFocus.com

For reference, Sean Smith ranks as the No. 11 overall cornerback and Brandon Flowers No. 74.

Here's a look at the first five cornerbacks taken in the 2013 NFL draft.

First five CB's taken in 2013 NFL Draft Pick Player Team PFF Rank 9 Dee Milliner New York Jets T-98 12 D.J. Hayden Oakland Raiders T-98 22 Desmond Trufant Atlanta Falcons 18 25 Xavier Rhodes Minnesota Vikings 60 36 Darius Slay Detroit Lions 102 ProFootballFocus.com

It's too early to make bold statements on any of these players because they've barely played a half of an NFL season.

But the early returns for Copper look good in comparison to the other cornerbacks, who were much bigger investments to their respective NFL teams.

Cornerback is such a difficult position to play in the NFL at any level of experience, but to thrive as Cooper is right now as a seventh-round, waiver-pickup rookie is almost unheard of.

In college as a spot-starter and rotational player at Rutgers, Cooper had just one interception in three years. Through nine NFL games, Cooper has two interceptions, and he forced a fumble in last week's victory over the Buffalo Bills.

Film Room

What's been most impressive from Cooper is that he's shown the ability to do the small things in regards to technique that separate him from not just other rookies, but also from most NFL cornerbacks.

This screenshot below illustrates one of those "smaller details."

On this pass attempt to New York Giants receiver Hakeem Nicks, Cooper does a great job of making a play on the ball as he puts his left arm between the receivers' arms to break up the pass. That's exactly how you're taught, and it works perfectly on this play.

Then against the Houston Texans and rookie receiver DeAndre Hopkins, Cooper does something similar while attempting to defend the fade in the end zone.

Cooper initially feels the fade route and jumps to beat Hopkins to the corner. When he notices the ball is underthrown, he doesn't panic or grab; he simply raises his arm and fights to get to the catch point.

He knocks the ball down and preserves the Chiefs' 14-10 lead in the second half. The Texans were forced to kick a field goal after this play.

On this slant play against the Oakland Raiders, Cooper recognized the route from a similar formation earlier in the game, via Terez A. Paylor of The Kansas City Star:

It was a play they had some success on earlier in the game. I saw the same formation, the same splits. So through film study and things like that, you start to pick up on stuff. They showed that play and formation so I just (took advantage of) the opportunity.

Cooper has gotten a lot of credit for his ability to press receivers and use his 6'2" frame to alter routes off the line of scrimmage. But here's a look at him lined up in off-man coverage.

He's lined up on Raiders receiver Denarius Moore, who had beaten him and Eric Berry for a touchdown early in this game.

You can see that Cooper instantly recognizes the play (as he stated) and jumps the route for an interception.

Cooper is taking what he sees in film study during the week and throughout the game and processing it quickly enough to make plays.

In this last photo, you'll see Terrelle Pryor and the Raiders challenge Cooper deep, which he plays perfectly and breaks up the pass.

Cooper ran stride-for-stride down the field with receiver Rod Streater and put himself in perfect position to make a play on the ball.

His Play Affecting the Whole Defense

It's not just that Cooper has proven that he's not a liability when placed outside. He's allowing the Chiefs defense to change what it's doing with the rest of the personnel, namely Brandon Flowers.

Flowers has been able to spend more time in the slot with Smith and Cooper taking the outside. This has led to less playing time for Robinson, but Flowers has been able to bring some pressure blitzing from the slot-corner position in Sutton's aggressive scheme.

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In his last four games (the heart of Cooper's emergence), Flowers has picked up three quarterback pressures and a sack from the slot.

The defensive look with Smith and Cooper on the outside gives the Chiefs two big, physical cornerbacks on the outside and the smaller, quicker Flowers on the inside.

This allows Sutton to be more creative with his blitz packages, with Flowers' ability to play inside or outside and his quickness to get to the quarterback. The Chiefs have blitzed Kendrick Lewis, their free safety, on a number of occasions this year as well.

Adding a quality defensive back that you can trust in situations like the one above with Streater on the deep pass gives confidence to the rest of the defense and to the coordinator that you can handle being put in one-on-one coverage when your teammates are blitzing.

Cooper as Defensive Rookie of the Year

If there's anyone who could challenge Bills linebacker Kiko Alonso right now for Defensive Rookie of the Year, it's Cooper.

He's playing a marquee position on the NFL's top-ranked scoring defense, but just like the Chiefs team as a whole, most people are in the "wait and see how they do against the Denver Broncos" camp.

That matchup in two weeks is going to tell us a lot about the Chiefs team, both offensively and defensively.

Many believe that Cooper's emergence sets the Chiefs up well against the Broncos offense: Smith and Cooper matching up with Demaryius Thomas and Eric Decker on the outside, Brandon Flowers on Wes Welker in the slot and Eric Berry on Julius Thomas.

The Chiefs have been prone to the big play defensively so far this season, and they haven't faced a quarterback in the same ballpark as Peyton Manning.

Cooper and the rest of the Chiefs defense will have the stage on Sunday Night Football against Manning and the Broncos offense in two weeks. If Cooper and the Chiefs are able to put together a solid performance in that game, expect the Defensive Rookie of the Year buzz to grow immensely.