Underclassmen always impact the NFL Draft, and the league is bracing for a record number of non-senior entrants into the 2009 event. The talent at several positions, including quarterback, running back, wide receiver, defensive line and cornerback, would be significantly upgraded with an infusion of underclassmen talent.

Here's a list of the top draft eligible non-seniors at each position, along with their present draft ranking and a prognosis on if they'll be playing on Sundays next year. Underclassmen have until Jan. 15 to declare their eligibility for the draft in April.

Matt Stafford/Georgia: NFL scouts predict the Georgia gunslinger would be the first quarterback selected if he entered the draft. By all accounts, Stafford plans to do so. He is considered a top five pick by some, but the consensus is Stafford is more likely to land in the middle of round one.

Mark Sanchez/USC: Sanchez rates just below Stafford as a late first-round pick. He's given different signs as to whether he'll enter the draft. It could be a while before he makes a final decision.

Sam Bradford/Oklahoma: His accuracy has been compared to Peyton Manning's, yet scouts still have questions about the Heisman Trophy winner's ability to play in an NFL style offense. He grades out as a second-round choice; most expect him to return to Norman next season.

Josh Freeman/Kansas State: The Wildcats' strong-armed passer can hurl the football a country mile, yet his accuracy is very erratic. He is expected to enter the draft and most league insiders feel a team will fall in love with his physical skills and select him much earlier than warranted.

Others to watch: Colt McCoy/Texas, Nate Davis/Ball State, Tim Tebow/Florida.

Chris Wells/Ohio State: Wells is a tough north/south runner who hammers opponents on the inside. He's expected to enter the draft and will be taken in the top half of round one.

Knowshon Moreno/Georgia: Scouts expect Moreno to follow teammate Stafford to the NFL and become another first-round pick from the Georgia program. Moreno will battle Wells for the honor of being the first running back drafted.

Shonn Greene/Iowa: Greene caught the Hawkeyes faithful by surprise as the first-year starter. Though he hadn't played in 2007, he ran roughshod over the competition this season. He is expected to enter the draft and become an early second-round choice.

Donald Brown/Connecticut: He put together a tremendous season, impressing scouts with a variety of ball-carrying skills. He's said to be leaning towards entering the draft, where he would be a second-round choice.

C.J. Spiller/Clemson: Spiller displayed game-breaking skills the past two years, though injuries reduced his effectiveness in '08. Scouts favor Spiller returning for his senior season to prove he can be a feature runner for an entire year, but Spiller is likely to enter the draft and become a top 45 selection.

Others to watch: LeSean McCoy/Pittsburgh, DeMarco Murray/Oklahoma

Michael Crabtree/WR/Texas Tech: Scouts expect the Red Raiders' dominant wideout to enter the draft, contrary to his public pronouncements about returning to Lubbock. Crabtree will end up as a top six selection in April.

Jermaine Gresham/TE/Oklahoma: Gresham is a home run-hitting tight end who is hard to defend. He is expected to enter the draft and will be chosen in the first dozen picks.

Jeremy Maclin/WR/Missouri: Maclin rounds out the trio of Big 12 game breakers at wideout. He possesses breakaway speed and can score from anywhere on the field. Maclin is giving serious consideration to making the jump; he'll go in the middle of round one if he opts for the NFL.

Percy Harvin/WR/Florida: The Gators multi-purpose skill player is a threat to score anytime he touches the ball. Sources in Gainesville say they expect Harvin to enter the draft. If he does, he'll slide into the bottom third of the first round.

Jared Cook/TE/South Carolina: Cook is one of the better pass-catching tight ends in the nation. Many in the scouting community think he will be the second player selected at the position if he enters the draft, which Cook is expected to do.

Darrius Heyward-Bey/WR/Maryland: Heyward-Bey is another pass catcher with enough home-run speed to strike fear in defensive backs. His production was spotty this year, which will depress his draft grade. Look for Heyward-Bey to make the jump to the NFL and end up in round two.

Others to watch: Jacoby Ford/WR/Clemson, Brandon LaFell/WR/LSU, Dennis Pitta/TE/BYU, Damian Williams/WR/USC, Kenny Britt/Rutgers.

Andre Smith/OT/Alabama: The Tide's dominant left tackle is expected to enter the draft and end up as a top five pick, possibly as the first selection of April's event.

Russell Okung/OT/Oklahoma State: He is one of the most complete tackles in this group. He's an exceptional pass protector who moves defenders off the line run blocking. Okung is on the fence about where he'll be playing next year even though he grades out as a first-round pick.

Eben Britton/OT/Arizona: Britton, a three-year starter for Arizona, offers terrific size and upside. Scouts feel he lacks a complete game and is being overrated. He has enough talent to be a top 45 choice. Sources close to the Wildcats program feel Britton is leaning towards entering the draft.

Trent Williams/OT/Oklahoma: Williams became a full-time starter this season and opened a lot of eyes with his outstanding play. Though he ranks as a second-round choice, he's likely to return to OU.

Others to watch: Ciron Black/OT/LSU, Thomas Austin/C-G/Clemson, Matt Tennant/C/Boston College, Josh McNeil/C/Tennessee, John Estes/C/Hawaii.

Everette Brown/DE/Florida Sate: Brown put together a terrific season and pulled the pieces of his game together. Scouts consider him one of the most athletic pass rushers in the nation. Brown looks like he's headed for the draft, where he'll be a first-round choice.

Greg Hardy/DE/Mississippi: Hardy is another tremendous athlete and offers as much potential as any other defensive lineman in the county. He's likely to enter the draft and be a first-round pick.

Terrence Cody/NT/Alabama: Mount Cody dominated the opposition during his initial season with the Tide. He's large, powerful and nearly impossible to block. Alabama insiders think Cody will enter the draft. He'll end up in round one.

George Selvie/DE/South Florida: Selvie comes off a slightly disappointing campaign after being one of the nation's most feared pass rushers the previous season. He still grades out as a first-round pick, though he'd be selected towards the end of the frame rather than the beginning. It may not matter as the word in Tampa has Selvie returning to USF.

DeMarcus Granger/DT/Oklahoma: Granger is a bigger version of Tommie Harris but possesses the same quickness and explosion of the former Sooner All American. He hasn't decided on the draft but would be selected in the first round, like Harris, if he leaves college.

Geno Atkins/DT/Georgia: The Bulldogs fierce tackle is undersized yet explosive and tough to block. He presently ranks as a second-round choice but has stated he will return to Athens for his senior campaign.

Sen'Derrick Marks/DT/Auburn: Marks is another small yet quick one-gap tackle prospect. He's made overtures that he'll enter the draft, in part because of Auburn's handling of the Tommy Tuberville situation. He would be selected in the middle of round two.

Paul Kruger/DE-OLB/Utah: Kruger moved off the radar screen in 2008, even though he pieced together one of the most dominant seasons of any defender in college football. He's also expected to enter the draft, where he would go in the second round. But be aware: Kruger is the type of athlete who will tear up the Combine next year and proceed to skyrocket up draft boards.

Chris Baker/DL/Hampton: Baker, who began his college career at Penn State, tore up the opposition during his first year at Hampton. He's an exceptional talent who can play a variety of positions on the defensive line. Sources close to Baker say he is leaning towards entering the draft, where he will be a second-round choice.

Others to watch: Auston English/Oklahoma, Gerald McCoy/DT/Oklahoma, Arthur Jones/Syracuse.

Brandon Spikes/ILB/Florida: Spikes is turning into one of the most dominant and complete Gator linebackers in recent years. He's expected to enter the draft and could slide into the draft's initial 32 selections.

Mark Herzlich/OLB/Boston College: Herzlich developed into a complete three-down defender this season and is celebrated as one of the top defenders in the ACC. He grades out as a first rounder but all sources have indicated Herzlich will return to Boston College for his senior campaign.

Joe Pawelek/ILB/Baylor: The Bears tackling machine is an omni-present force. Even with a good crop of inside linebackers in the draft, Pawelek is expected to throw his hat into the ring and will likely be chosen in round two.

Gerald McGrath/LB/Southern Mississippi: McGrath has been a tackling machine for Southern Mississippi, recording 100 or more tackles the past three years. The junior is uncertain as to his next move but grades as a second-round pick if he opts for the draft.

Others to watch: Sergio Kindle, Jerry Hughes/TCU, Sean Weatherspoon/Missouri, Rico McCoy/Tennessee, Antonio Coleman/Auburn.

Taylor Mays/S/USC: Mays is a complete safety and one of the best all-around defensive backs in the nation. Odds are he will enter the draft and be a top 10 choice.

D.J. Moore/CB/Vanderbilt: Moore saw his game take off this season and the Vandy corner made great progress on the field. He can help out any team in a number of ways. Moore is leaning towards entering the draft, where he would be the second cornerback selected in the first round.

Vontae Davis/CB/Illinois: Davis is a terrific talent who flashes ability. His play has been spotty at times but that does not shake his confidence. Expect Davis to enter the draft and be selected at the top of round two.

Sean Smith/CB/Utah: Smith has the size (6-foot-2, 212 pounds) and speed (4.35 in the 40) that makes scouts take notice. His upside is outstanding because he offers ability at corner and safety. Indicators point to Smith entering the draft, where he could slip into the late part of round one.

Trevard Lindley/CB/Kentucky: The Wildcats corner has shown steady improvement the past two years. Lindley, who grades as a second-round pick, is uncertain as to whether or not he'll enter the draft.

Others to watch: Captain Munnerlyn/South Carolina, Emmanuel Cook/South Carolina, Kyle Wilson/Boise State, Syd'Quan Thompson/California

SI Apps
We've Got Apps Too
Get expert analysis, unrivaled access, and the award-winning storytelling only SI can provide - from Peter King, Tom Verducci, Lee Jenkins, Seth Davis, and more - delivered straight to you, along with up-to-the-minute news and live scores.