With the NFL Scouting Combine beginning on February 22, NFL Network's Mike Mayock updates his position-by-position rankings for the 2012 NFL Draft. Changes from last month's initial rankings are noted below each position.

Quarterback

1. Andrew Luck, Stanford
2. Robert Griffin III, Baylor
3. Ryan Tannehill, Texas A&M
4. Brandon Weeden, Oklahoma State
5. Nick Foles, Arizona

New entries: Weeden, Foles

Running Back

1. Trent Richardson, Alabama
2. David Wilson, Virginia Tech
3. Lamar Miller, Miami (Fla.)
4. Doug Martin, Boise State
5. LaMichael James, Oregon

Wide Receiver

1. Justin Blackmon, Oklahoma State
2. Kendall Wright, Baylor
3. Michael Floyd, Notre Dame
4. Rueben Randle, LSU
5. Alshon Jeffery, South Carolina

Rise: Wright
Fall: Floyd, Jeffery
New entry: Randle
Out: Wake Forest's Chris Givens

Tight End

1. Orson Charles, Georgia
2. Coby Fleener, Stanford
3. Dwayne Allen, Clemson
4. Deangelo Peterson, LSU
5. Ladarius Green, Louisiana-Lafayette

Rise: Charles
Fall: Allen, Green
New entry: Peterson
Out: Missouri's Michael Egnew

Tackle

1. Matt Kalil, USC
2. Riley Reiff, Iowa
3. Jonathan Martin, Stanford
4. Mike Adams, Ohio State
5. Cordy Glenn, Georgia

Rise: Kalil
Fall: Reiff
New entry: Glenn (switched groups from interior offensive lineman to tackle)
Out: Troy's James Brown, Florida State's Zebrie Sanders

Interior Offensive Lineman

1. David DeCastro, Stanford
2. Peter Konz, Wisconsin
3. Kevin Zeitler, Wisconsin
4. Amini Silatolu, Midwestern State
5. Kelechi Osemele, Iowa State

Fall: Osemele
New entry: Silatolu
Out: Glenn (switched groups from interior offensive lineman to tackle)

Defensive End

1. Melvin Ingram, South Carolina
2. Quinton Coples, North Carolina
3. Andre Branch, Clemson
4. Whitney Mercilus, Illinois
   T-5. Vinny Curry, Marshall
   T-5. Nick Perry, USC

Rise: Ingram, Branch
Fall: Coples, Mercilus, Perry
New entry: Curry
Out: Syracuse's Chandler Jones

Defensive Tackle

1. Michael Brockers, LSU
2. Jerel Worthy, Michigan State
3. Dontari Poe, Memphis
4. Devon Still, Penn State
   T-5. Fletcher Cox, Mississippi St.
   T-5. Kendall Reyes, UConn
   T-5. Brandon Thompson, Clemson

Rise: Brockers, Poe
Fall: Still, Thompson
New entry: Reyes

Linebacker

1. Courtney Upshaw, Alabama
2. Luke Kuechly, Boston College
3. Dont'a Hightower, Alabama
4. Ronnell Lewis, Oklahoma
5. Sean Spence, Miami (Fla.)

New entries: Lewis, Spence
Out: North Carolina's Zach Brown, Arizona State's Vontaze Burfict

Cornerback

1. Morris Claiborne, LSU
2. Dre Kirkpatrick, Alabama
3. Janoris Jenkins, North Alabama
4. Trumaine Johnson, Montana
5. Leonard Johnson, Iowa State

Rise: Kirkpatrick
Fall: Jenkins, Leonard Johnson
New entry: Trumaine Johnson
Out: Nebraska's Alfonzo Dennard

Safety

1. Mark Barron, Alabama
2. Harrison Smith, Notre Dame
3. George Iloka, Boise State
4. Markelle Martin, Oklahoma State
5. Phillip Thomas, Syracuse

New entry: Phillip Thomas
Out: South Carolina's Antonio Allen