QB David Ash
Heading into the 2013 season, there are several marquee starters on teams that have a lot to prove this year.
There's quarterback David Ash of Texas, who's been inconsistent since taking the reins in Austin and must now adapt to a new, uptempo style of offense.
John Hubert, the starting running back at Kansas State, must now prove he can carry the load on the ground without Collin Klein.
Then there are guys on the other side of the ball such as defensive end Stephon Tuitt of Notre Dame, who's got the task of replicating one of the nation's best defenses this season without Manti Te'o.
Here are seven of the biggest starters in college football that have a chip on their shoulder going into this season:
RB John Hubert
John Hubert has quietly been one of the best backs in the Big 12 over the past two seasons, rushing for a combined 1,917 yards and 18 scores since 2011.
However, what will be different about 2013 from the past two seasons is that Collin Klein, one of college football's best dual-threat quarterbacks ever, is not in Manhattan anymore.
Now, Hubert must prove that he alone can carry the weight of the ground attack on his shoulders rather than being the perfect complement to Klein.
The Wildcats have a quality offensive line with five returning starters on that unit, so Hubert will definitely have some help in becoming the main offensive threat for Bill Snyder.
Still, there's a huge difference in being the complementary back and being the go-to guy.
QB David Ash
David Ash is one of just two starting quarterbacks in the Big 12 this season that started for their team in Week 1 of last year. So in a league known for it's quarterback play, being one of only two returners carries the weight of heavy expectations.
That's a lot to handle for a guy who's been inconsistent at best since arriving at Austin.
In 2012, he threw for over 250 yards in a game six times but under 200 yards four times. His touchdown-to-interception ratio over his career is just 23-to-16.
While Ash made strides last season, many of those are wiped out now that the Longhorns are implementing a new, no-huddle offense.
Ash will have to prove to the nation that he can handle the added weight of making rapid-fire decisions in his junior year if the Longhorns want to have a successful year in 2013.
With no more Manti Te'o to make the game-changing plays on defense for the Fighting Irish, Stephon Tuitt will have to set the tone for his squad in 2013.
Last year, Tuitt had 45 tackles and 11 sacks, which perfectly complemented Te'o's Heisman runner-up season. But now, if Tuitt can't be the leader he's being asked to be in South Bend, Notre Dame's defense could take a significant step back.
Tuitt has certainly proven himself to be an excellent defensive end. But he'll need to take that next step to the elite level if he wants to help bring the Fighting Irish back to a BCS bowl game.
QB Casey Pachall
After only playing in four games last season before being suspended, leaving TCU altogether and entering rehab for drug and alcohol abuse, Pachall has to prove to himself, his team and the country that he's a changed man.
Pachall has already proven himself to be an elite quarterback on the field. In fact, as of now, he's probably the best quarterback in the Big 12.
But in his senior year, Pachall has to maintain his composure off the field if the Horned Frogs want a shot at winning a Big 12 title, which they certainly have this season.
According to J.D. Moore of TCU 360, Del Conte, the athletic director at TCU has been pleased with Pachall's progress.
"Casey Pachall has worked hard to follow all the guidelines set forth by the University for his return to TCU," Conte said. "We're excited to have him back as part of our campus community."
If Pachall can stay out of trouble, he could be one of the best quarterbacks in the country.
They don't call it a sophomore slump for nothing.
And with a new head coach in Mark Helfrich and Kenjon Barner gone, Oregon Ducks quarterback Marcus Mariota could be due for one.
As a freshman last year, Mariota was one of the best in the country. He threw for 2,677 yards and 32 touchdowns to just six picks.
However, Mariota now needs to prove that he can replicate that success despite the landscape around him changing drastically.
If Mariota can show that he can make the necessary adjustments in his sophomore season, he could put Oregon in the hunt for the BCS title.
Kevin Hogan took over the starting job last season against Colorado when Cardinal head coach David Shaw yanked Josh Nunes after two possessions.
Despite seeing significant playing action in only six games, Hogan threw for 1,096 yards and nine touchdowns.
Now he needs to prove that he wasn't a late-season wonder and that his success can be sustained over the course of the entire season.
Hogan has a terrific offensive line in front of him, so he won't be forced to make risky plays. If he can just manage the game effectively, he'll give the Cardinal the best chance to win.
Despite having not played a down of college football yet, Ole Miss defensive end Robert Nkemdiche already has a lot to prove to Rebels fans.
Obviously, it's not yet set that Nkemdiche will be a starting defensive end for the Rebels. But being the No. 1 recruit in the country, it's hard to imagine that he won't come in right away and see the field.
After spring practice ended and before Nkemdiche arrived on campus, Ole Miss released its depth chart. According to Hugh Kellenberger of the Clarion Ledger, the Rebels listed C.J. Johnson and Cameron Whigham as their two starters at defensive end. Johnson is the team's leading returner in sacks with 6.5, so expect Johnson and Nkemdiche to start.
Nkemdiche is the pride and glory of Hugh Freeze's heralded 2013 recruiting class. According to 247Sports, Nkemdiche is the No. 1 overall prospect in the entire nation for his class.
With those honors come high expectations.
Nkemdiche will be expected to make an immediate impact for the Rebels, a team that is looking to take a big step forward this season.
If he falters early, then Ole Miss may struggle to find a suitable replacement for someone who they thought was the best in the country in high school.