The limited career window of a college athlete offers so little time to make an impact. One bad season can permanently alter the perception of a player, especially when many earn starting jobs for only two years -- and, at most, four.

College football players are undercompensated, overworked students, yet the hopes and dreams of hundreds of thousands of fans and the job security of a multi-million dollar coach depends on them. Fair? Maybe not. But watching the maturation of players on the field is one of the most appealing parts of the game. This week we identify some of the most important players who will be under pressure to step up in the 2013 college football season, whether it's to elevate their game to a higher level, to replace the irreplaceable, or to help shift the direction of a program.

Quarterbacks under the microscope

Tommy Rees, QB, Notre Dame. Things that happened in the last year:

1) Rees, who was the starter in 2011 and for some of 2010, lost the job to redshirt freshman Everett Golson.

2) Notre Dame went undefeated in the regular season, mostly behind Golson, with Rees making a few appearances in a bizarre "closer" capacity.

3) Golson got kicked out of school, presumably putting the starting job back in the hands of Rees.

This is not exactly a common chain of events in college football. Yet here we are, and Rees, the interception-prone passer who still led a solid 2011 campaign, must follow up a season in which Notre Dame went to the national title game. Despite the embarrassing loss to Alabama, Notre Dame had its best season in 20 years, and now the test is whether or not a high level of success is sustainable, especially after so many wins were decided by one possession. Golson was far from perfect, but he allowed Notre Dame to start building a more up-tempo, downfield and complete offense around him. With Rees those plans have to slow down, because he doesn't possess the passing potential or running ability that Golson does. That's not to say Notre Dame can't succeed with Rees. The Irish won eight games in 2011, and no matter who the quarterback is, they're going to win with their defense in 2013. But Notre Dame will take a step back from an undefeated regular season. How big that step is could depend on Rees' ability to protect the ball and allow Notre Dame's defense to dictate the pace of the game.

Zach Mettenberger, QB, LSU. The best glimpse of Mettenberger's potential last year came against his toughest opponent. LSU may have lost to Alabama, but Mettenberger looked like a different player: poised, confident, and in command. He completed 24 of 35 passes for 298 yards -- his highest total of the season -- and a touchdown with no interceptions. That was the high point, though, and he finished the season with 2,609 yards, 12 touchdowns and seven interceptions, capped by a lackluster 120-yard outing against Clemson in the Chick-fil-A Bowl. Mettenberger's college career has been a strange journey. A four-star recruit in 2009, he signed with Georgia but was kicked off the team after one season; he then played one year at Butler Community College before transferring to LSU, where he spent a season behind Jordan Jefferson and Jarrett Lee before being anointed the savior of the offense last preseason.

Ultimately the LSU offense struggled again, for the most part, and now Cam Cameron -- who was let go by the Ravens in the middle of a Super Bowl season -- will try to get some kind of consistency out of this unit. That means Mettenberger, a senior, must adapt to the fourth offense of his college career, while dealing with a suspended running back, Jeremy Hill. There will be added pressure on his offense to be more dependable too, as the defense attempts to reload after a mass NFL exodus. With a brutal schedule, a revamped defense and a new offensive coordinator, LSU is one of the more intriguing teams to watch in college football this season, but if Mettenberger makes the leap, the Tigers will be national title contenders again.

Blake Bell, QB, Oklahoma. Here's your most often repeated stat of the offseason: Bell, Oklahoma's new starting quarterback, has rushed for 24 touchdowns but attempted only 20 passes in his college career. So Bell may be simultaneously overrated -- by those looking solely at Tebow-like situational player rushing numbers as an indication that he'll automatically be a star -- and underrated, at least by those who say he has no passing ability simply because he hasn't been given the opportunity to throw while waiting behind Landry Jones. The Belldozer goal-line package was generally effective for the Sooners, but now the former star quarterback recruit (listed as a pro-style QB, not a dual-threat, by Rivals) gets to prove that he has the arm to go with the physical running ability. In a wide-open but talented Big 12, Bell's play could make the difference between a conference title and the Buffalo Wild Wings Bowl.

Max Wittek, QB, USC. This could also be Cody Kessler or true freshman Max Browne, but for now let's operate under the assumption that Wittek opens the season as USC's starting quarterback. Recapping USC's failure to come close to meeting expectations in 2012 is well-trodden ground, so let's keep it brief: The offense wasn't awful, but Matt Barkley threw 15 interceptions in only 11 games, and despite the presence of Marqise Lee and Robert Woods at receiver, the passing game was often horizontal instead of vertical.

The inexperienced Wittek stepped in for the injured Barkley against Notre Dame and Georgia Tech but threw for a total of only 388 yards with five interceptions. All three QB candidates are highly touted recruits, though, and whoever starts will have the luxury of Lee, the nation's best receiver, breakout candidate Nelson Agholor as Woods' replacement and talented tight ends. There's a wealth of talent, as always. It's the play of the quarterback that could determine the fate of coach Lane Kiffin.

Keith Price, QB, Washington. Rarely do you see the kind of fall from a quarterback's first season as a starter to his second that Price experienced:

Washington's yards per play in 2011: 6.2 (24th)
Price's QB rating in 2011: 161.9 (7th)

Washington's yards per play in 2012: 5.1 (102nd)
Price's QB rating in 2012: 122.4 (80th)

After showing so much potential as a sophomore, Price fizzled as a junior, although both campaigns resulted in a 7-6 record for the Huskies. But after struggling to adapt to a young receiving corps, there should be nowhere to go but up with what's now an experienced and talented supporting cast. Price is backed by 1,400-yard rusher Bishop Sankey, the nation's best tight end, Austin Seferian-Jenkins, one of the Pac-12's best wide receivers, Kasen Williams, and touted freshman receiver Damore'ea Stringfellow. Last year's drop-off coincided with the loss of offensive coordinator Doug Nussmeier to Alabama, and now his replacement, Eric Kiesau will attempt to rebound with coach Steve Sarkisian by moving to a more up-tempo approach. After four years of all-around mediocrity, Sarkisian needs some forward momentum, and in 2013 that starts with the re-emergence of Price against a brutal top half of the Pac-12 North.

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Attempting to poke holes in national contenders 

Deion Belue, CB, Alabama. OK, so Alabama led the nation in scoring defense last year … and total defense … and run defense … and finished seventh in pass defense. Hardly anyone moved the ball on the Crimson Tide, and that's unlikely to change much. Still, if an opponent had any success on offense, it was usually through the air: Johnny Manziel won the Heisman against Alabama, Mettenberger may have played his best game and Georgia's Aaron Murray made some plays in a tight game. Mostly, teams wisely avoided Dee Milliner (except Notre Dame, for some reason), who was drafted ninth overall by the Jets.

That leaves Belue, a senior and former juco transfer, as the experienced returning cornerback. Belue was occasionally picked on last year, and he'll see better receivers with Milliner gone, unless promising sophomore Geno Smith rises to the top corner role. Alabama's front seven will be great, of course, but the system also relies on cornerbacks stepping up and locking down the outside. Two of Alabama's three best quarterback opponents are on the schedule to start the season -- Virginia Tech's Logan Thomas and Manziel -- so we'll quickly get a taste of how the Alabama corners are shaping up. Knowing Alabama's history over the past few years, more than likely they'll be just fine.

Ty Montgomery, WR, Stanford. With Pep Hamilton off to reunite with Andrew Luck in Indianapolis, former run game coordinator Mike Bloomgren takes charge of the entire Stanford offense (as the "Andrew Luck Director of Offense"), one that is expected to become more vertical this year. Bloomgren has the perfect centerpiece in sophomore quarterback Kevin Hogan, but the supporting cast is up in the air, as two tight ends left early for the NFL (Zach Ertz and Levine Toilolo) and running back Stepfan Taylor is also gone. Ertz and Taylor alone combined for 110 of the team's 240 receptions, while Montgomery is the leading returning wide receiver with just 26. A former four-star recruit, Montgomery struggled with knee issues last year and failed to build on a breakout Fiesta Bowl as a freshman. Now, with so much production needing to be replaced in the passing game, he's the No. 1 candidate to emerge as a go-to target for Hogan out wide.

Steven Jenkins, LB, Texas A&M. All told, the Texas A&M defense wasn't that bad last year, considering it allowed only 21.8 points per game despite finishing 104th in forced turnovers. Still, only four starters return to a unit that was especially weak against the pass, although perhaps that perception is slightly out-of-whack because of the 59-57 track meet against Louisiana Tech. All-American pass rusher Damontre Moore (12.5 sacks) is gone, and so are linebackers Sean Porter and Jonathan Stewart, leaving Jenkins as the returning leader in sacks with just two. The team's third-leading tackler last season, Jenkins was suspended one game to open last season and finished with a torn labrum in the Cotton Bowl that cost him spring practice. Texas A&M's schedule isn't exactly littered with explosive offenses, but some semblance of a pass rush needs to develop in the absence of Moore, and Jenkins is one of the few players returning with experience.

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Playmakers wanted

Quinton Dunbar, WR, Florida. It's not surprising that the Gators finished 92nd in yards per play last year, given their preference for running the ball up the middle and their complete lack of playmakers in the receiving corps. The Gators' best receiving threat by far was tight end Jordan Reed, but he left early for the NFL, leaving the versatile Dunbar as the most productive returning receiver after catching 36 passes for 383 yards and four touchdowns. Needless to say, the Gators need much, much more to make Jeff Driskel a more effective passer after he finished 11th in the SEC in efficiency and Florida finished 106th nationally in sacks allowed despite attempting only 22 passes per game. Driskel needs to play better, but it's nearly impossible if his receivers aren't getting open and making plays. Florida has a problem when Loucheiz Purifoy, a preseason All-American cornerback, may also be its most dangerous option at receiver.

Dorial Green-Beckham, WR, Missouri. Arguably the No. 1 overall prospect in the class of 2012, Green-Beckham opted to stay in his home state and play for Missouri as part of its foray into the SEC. The Tigers were a bust last year, plagued by injuries at quarterback (James Franklin) and running back (Henry Josey, who missed the entire season), but if nothing else they should be healthier. Top recruit or not, it's hard to ever fault a true freshman for a slow start, but now Missouri will need to start seeing more out of the 6-foot-6, 220-pound Green-Beckham, who did flash his big-play ability toward the end of the season with four touchdowns in the final three games. The Tigers' spread offense, effective for several years in the Big 12, was neutered by a schedule that featured Georgia, South Carolina, Alabama and Florida last year, and a turnaround needs an impact playmaker. That's what Green-Beckham was recruited to be, and Missouri can't afford to have its leading receiver catch 46 passes for 509 yards again.

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Stop the punting

Andrew Maxwell, QB, Michigan State. Michigan State punted 80 times last season, more than all but five teams nationally (see below for Virginia Tech and Rutgers, who punted 81 times each), despite the running of Le'Veon Bell, who finished third with an average of 137.9 yards per game. Of course, Bell also led the nation in carries, and Michigan State ranked 111th in yards per play. That problem can be traced to one of the least efficient passing games in America. The Spartans struggled to make the transition from Kirk Cousins to Maxwell, who completed 52.5 percent of his passes with 13 touchdowns, nine interceptions and an average of only 5.8 yards per attempt. As always, it's unfair to blame Maxwell for all the struggles, as he got little help from his receiving corps, but he needs to make a significant leap early or run the risk of permanently losing his job to sophomore Connor Cook.

J.C. Coleman, RB, Virginia Tech. From David Wilson to Darren Evans to Ryan Williams to Kevin Jones to Lee Suggs, Virginia Tech hasn't had a shortage of effective running backs over the last decade. Last year was an exception. While everyone has been busy criticizing quarterback Logan Thomas for not playing up to his potential as the Hokies plummeted to 7-6 (their first season without 10 wins since joining the ACC), he didn't get much help either. That's not to excuse Thomas' play -- he threw 16 picks and completed only 51.3 percent of his passes -- but he was the team's leading rusher with 524 yards, and that can't happen again. So, Coleman, a 5-foot-8, 177-pound freshman last year, was the team's leading running back but finished 23rd in the conference in rushing. He may need to lead the team again now as Michael Holmes deals with the fallout from his legal problems. Obviously, Thomas needs to protect the ball, but it would help if someone like Coleman (or redshirt freshman Trey Edmunds) can emerge to stabilize an offense that has typically been balanced and will transition to a new offense under Scot Loeffler.

Savon Huggins, RB, Rutgers. In year one under Kyle Flood, the Scarlet Knights mostly won by suffocating opponents with defense, but that can't be everything. Their stagnant offense resulted in 6.2 punts per game, and they finished 102nd in net punting, meaning it's actually hard to believe they won nine games. Rutgers actually does have an NFL-caliber receiver in Brandon Coleman, but QB Gary Nova is firmly in "game-manager" territory, which can adequately get the job done only if every other aspect of the team is clicking. That means Huggins is front and center. A former four-star recruit, Huggins couldn't beat out Jawan Jamison, who ran for 1,075 yards but then unexpectedly left for the draft after his redshirt sophomore season (and fell to the 228th pick). Jamison's departure puts the starting job firmly in the hands of Huggins, now a junior, who averaged just 3.4 yards on 119 carries last year. The Scarlet Knights already scored only 21.5 points per game -- 43 points total in their last four games against Cincinnati, Pitt, Louisville and Virginia Tech -- meaning they desperately need Huggins to emerge as a dependable threat out of the backfield if they have any hope of challenging Louisville, the heavy favorite in the American Athletic Conference. The whole ball-control idea won't work if they can't sustain offense on the ground.

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Contact me at matt.brown@sportsonearth.com and follow me on Twitter @MattBrownSoE.