College football experts typically discuss star players when debating which teams are better than others, but backups also play a very important role on every team.
Depth is almost as important as starting talent in a sport like football with so many injuries, and Iowa knows that first hand, after sustaining a number of injuries at running back and linebacker last season.
The Hawkeyes are in a rebuilding year, and while they lack star power, they do have a number of experienced players and a number of solid second-string players.
Check out Iowa's best backups of 2011.
Davis, a senior, likely won't be a starter during the 2011 season, but he has become a solid contributor for Iowa over the years.
Due to a number of injuries at linebacker, Davis has been given a lot of playing time over the last two seasons, especially for a backup.
He will have more opportunities to play this season when filling in for starting MLB James Morris and may be called upon to start once again if injuries rattle the linebacker corps.
Mossbrucker was the starting kicker for Iowa in 2008, but lost the starting job last year to true freshman Michael Meyer.
However, Mossbrucker is still a very capable kicker and may be called upon to relieve Meyer at times, as he was last season.
In 2008, Kirk Ferentz chose Daniel Murray to take a game-winning kick against No. 3 Penn State instead of the starter, Mossbrucker, because Murray had more experience. If a similar scenario arises this season, Mossbrucker could get the call.
Fiedorowicz was one of the most highly touted recruits in Iowa's 2010 recruiting class, and while he didn't have a major presence on the field last season as a third-string tight end, he will be a second-string tight end this season and should have a bigger impact.
Fiedorowicz has a very big frame and will be useful in both blocking and pass-catching situations.
Iowa employs a number of two-tight end sets, meaning he will likely be an influential player in the offense despite being a backup.
Castillo has seen a lot of playing time over the past few years and has even received a few starts due to injuries.
He definitely has potential, but has made a few "rookie" mistakes when given chances.
Now, with more experience, he will need to step up and may even be given a chance to start if the Hawkeyes decide to switch Micah Hyde to safety.
White has been hanging around for the last couple of years, and thanks to a number of injuries, transfers and suspensions, he has worked his way up the depth chart.
He won't win the starting job, but the starter, Marcus Coker, is a physical runner who will take a lot of hits, and White will be called on to relieve him a lot, especially early in the season.
White may be passed up for the backup role by one of Iowa's talented true freshmen—Mikail McCall or Jordan Canzeri—but he will be a vital player early in the year.
While Iowa returns star wide receiver Marvin McNutt, its depth and experience is relatively low at that position.
Starting alongside McNutt will be Keenan Davis, who should improve in his first year as the starter, but there is no experience after that.
Martin-Manley was a member of the 2010 recruiting class, and while the Iowa coaches say he still has a long way to go, he seems poised to be the Hawkeyes' youngest starting receiver.
Martin-Manley has also received numerous endorsements from former Iowa star Derrell Johnson-Koulianos, who has that he is the future of the Hawkeyes receiving corps.
Iowa's last punter, Ryan Donahue, was picked up by the Detroit Lions today and figures to make an NFL roster. He was one of the best punters in the Big Ten, and maybe the country, last season and has an outstanding leg.
For the last few years, Iowa has been pretty much automatic in the punting game, but it will be much more inexperienced this season. Eric Guthrie is listed as the starter for now, but expect backup Jonny Mullings to get a look as well.
Mullings, who is originally from Australia, has a strong leg and could fill in if Guthrie is inconsistent.
Iowa will need to replace 75 percent of its defensive line this season, as stars Adrian Clayborn, Christian Ballard and Karl Klug all depart. Defensive end Broderick Binns and defensive tackle Mike Daniels both have experience, but the line as a whole will be very inexperienced.
Davis, a redshirt freshman, was a star member of the 2010 recruiting class, has a huge frame and could see significant playing time even if he isn't given a starting job.
He likely won't be a starter early in the season, as Kirk Ferentz likes to go with experience, but he should be in a rotation and could earn a starting spot later in the year.