Top 5 on defense: Who's up, who's down?

In part two of the National Football Post's position rankings series, we turn our attention to defense. With some major changes in the top five on our position draft boards, we break down prospects on the rise and those who are starting to fall.

Aaron Maybin.

(Scott Boehm/Getty Images)

Defensive Ends
1. Aaron Maybin, Penn State (6-4, 250)
2. Robert Ayers, Tennessee (6-3, 272)
3. Everette Brown, Florida State (6-2, 256)
4. Brian Orakpo, Texas (6-3, 263)
5. Tyson Jackson, LSU (6-4, 296)

Penn State's Maybin is the top pure pass rusher in this year's draft, which is the main reason he's No. 1 on my board. He displays a great first step off the edge and is always the first defensive lineman moving off the snap. He possesses a long frame and will continue to add weight and get stronger at the next level. Ranking second is Ayers, whose combination of burst, fluidity and power should make him an attractive option in the first half of Round 1. Brown is a bit undersized and could be viewed as a 3-4 OLB, but he has the first step and explosion off the edge to be a consistent pass-rush threat.

The real surprise is that I moved Orakpo, the consensus No. 1 defensive end on most draft boards, to fourth. The more tape I watch of him, the less I feel he has the first step to consistently reach the corner and get after the passer. He doesn't play as strong as his weight room numbers indicate, and I don't think he has the fluidity to play OLB in a 3-4. No. 5 is Jackson, a powerful, long-armed lineman who has the versatility to play DE in both a 4-3 and 3-4 scheme. He can even slide inside on passing downs as a pass rushing DT. He is a big, strong athlete who brings a lot of versatility to a defense and should come off the board in the first round.

Defensive Tackles
1. B.J. Raji, Boston College (6-2, 337)
2. Jarron Gilbert, San Jose State (6-5, 288)
3. Peria Jerry, Mississippi (6-2, 299)
4. Evander Hood, Missouri (6-3, 300)
5. Sen'Derrick Marks, Auburn (6-2, 306)

Raji still ranks as the nation's top defensive tackle prospect and is one of my favorite prospects in this draft. He displays a rare first step for a man his size and knows how to push the pocket and eat up run lanes inside. Second is Gilbert, a versatile lineman who has the ability to play in either a 3-4 or 4-3 scheme. Gilbert made a living in opponents' backfields last season and has the burst, power and length to create plays versus the run and pass. He is simply one of the draft's top defensive linemen and has the ability to be effective in any scheme and at any position.

A trio of three-technique tackles finish out the rankings as Jerry, Hood and Marks grade out similarly to each other. However, Jerry gets the nod because of his non-stop motor and strong base. He has the ability to hold up against the run a bit better than Hood and Marks and should develop into a disruptive interior lineman early in his career.

Aaron Curry.

(Scott Boehm/Getty Images)

Outside Linebackers
1. Aaron Curry, Wake Forest (6-2, 254)
2. Connor Barwin, Cincinnati (6-4, 256)
3. Clay Matthews, USC (6-3, 240)
4. Brian Cushing, USC (6-3, 243)
5. Larry English, Northern Illinois (6-2, 255)

Curry remains the consensus No. 1 overall outside linebacker and appears headed toward a top-five pick. He displays impressive size, closing speed and power for the position and has the versatility to line up at any linebacker spot in either a 3-4 or 4-3 – although I feel his best fit is outside in a 4-3 scheme. Barwin, who's been flying up draft boards ever since he made the switch to defense in his senior season, possesses impressive athletic tools. His combination of instincts and motor makes him an intriguing 3-4 outside linebacker. He still has a bit of developing to do from a technique standpoint, but he offers more upside than any of the linebackers listed below him.

A pair of USC players come in at Nos. 3 and 4 and look to be the most polished of the group. Matthews is a natural football player who exhibits good fluidity and change-of-direction skills. He has the makings of a successful three-down backer in the NFL. Cushing plays with the same type of instincts and motor as Matthews, although I don't see the same fluidity to his game that would warrant him playing on third down. I think the best fit for Cushing would be inside in a 3-4 scheme. English, who will likely be asked to make the transition to OLB in a 3-4 at the next level, was a productive pass rusher in college, but I don't see the flexibility in his stance or the burst to consistently reach the edge in the NFL. However, he should be a good fit standing up in a 3-4 scheme and using his closing speed to get after the QB.

Inside Linebackers
1. Rey Maualuga, USC (6-2, 249)
2. James Laurinaitis, Ohio State (6-2, 244)
3. Frantz Joseph, Florida Atlantic (6-1, 242)
4. Darry Beckwith, LSU (6-1, 234)
5. Scott McKillop, Pittsburgh (6-1, 244)

Maualuga still sits atop our MLB rankings because of his physical presence inside the box and his ability to make plays at the line of scrimmage. He doesn't come without flaws as he's a bit stiff in coverage, but he should come off the board some time during the mid/late first round. Laurinaitis, who might be the most polished of any linebacker in the class, reads and reacts quickly and is always flowing toward the ball. He's a much better athlete than his measurables would lead you to believe and has one of the highest ceilings of any prospect in the draft.

Joseph is a bit of a surprise at the third spot, but he's been moving up draft boards in recent weeks. He's an ideal downhill linebacker with impressive power and good closing speed. He plays much faster than his times indicate and always seems to be around the ball. He may be only a two-down player in the NFL, but that's the direction more teams are going to with their starting middle linebacker spot. Senior Bowl standouts Beckwith and McKillop round out the list. Beckwith is pretty good athlete but plays more like a battering ram when attacking downhill. McKillop, on the other hand, relies on his instincts and savvy and always seems to be in position to make plays on the ball. It doesn't always look pretty, but he'll find a way to win a starting role in the NFL.

Sean Smith.

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Cornerbacks
1. Sean Smith, Utah (6-3, 214)
2. Malcolm Jenkins, Ohio State (6-0, 204)
3. Alphonso Smith, Wake Forest (5-9, 193)
4. D.J. Moore, Vanderbilt (5-10, 192)
5. Vontae Davis, Illinois (5-11, 203)

It's rare to find a cornerback with the size, fluidity and footwork that Sean Smith possesses, and this type of skill set is the main reason he's No. 1 on my board. I think Smith might have the most upside of any player in the draft, and with some time to improve on his technique he has the ability to become a very good man-to-man corner. Jenkins slips to No. 2 on our board but is still considered one of the nation's top cover men. He may be a bit scheme limited at the next level, although he has the balance and body control to make plays on the ball. Senior Alphonso Smith might be sitting atop the cornerback rankings if he were three inches taller. He possesses elite footwork, quickness and fluidity in and out of his breaks and is difficult to gain separation from. However, he's undersized and can be boxed out too easily down the field.

Juniors Moore and Davis make up the final two spots. Moore has not timed well this postseason but showcases some of the best closing speed in the draft. He has a smooth, compact backpedal and is always balanced and in position to make a play on the ball. On the other hand, Davis may have the best skill set of any corner but is too inconsistent with his footwork and technique. He isn't real compact, displays a sloppy transition and looks like a boom or bust prospect.

Safeties
1. Sherrod Martin, Troy (6-1, 198)
2. William Moore, Missouri (6-0, 221)
3. Rashad Johnson, Alabama (5-11, 203)
4. Chip Vaughn, Wake Forest (6-2 221)
5. Patrick Chung, Oregon (5-11, 212)

Martin, the versatile defensive back from Troy, is being considered at both the free safety and cornerback spots. He's one of the smoothest DBs in this year's class and has the ability to make it at either position. However, his ball skills and impressive range in the center field-type role scream ball-hawking safety. Moore entered last season as the nation's top safety prospect, but an injury-riddled senior year caused his draft stock to fall. He's finally healthy and is starting to run and perform the way many scouts expected. There's a bit of an unknown concerning Moore and his pedestrian-like senior year, but his stellar play as a junior has me convinced he was simply playing hurt.

Rashad Johnson, one of the nation's most instinctive defensive back, ranks third in the class. He's a ball-hawking safety who consistently reads the action quickly and is always flowing toward the play. He's a lot more physical than his frame indicates and should come off the board some time during the second or third round. Vaughn and Chung round out the group. Both are physical, hard-hitting defensive backs, although Vaughn displays much better range and fluidity in coverage. Chung gets by on his instincts, but he doesn't display the same type of recovery speed possessed by Vaughn.