After going 12-0 in Urban Meyer's first year as head coach, many expect Ohio State to enter the 2013 season as one of just a handful of favorites to reach the national title game.
With superstar quarterback Braxton Miller and eight other starters expected to return to an offense that averaged over 37 points per game in 2012, there's plenty of reason for optimism in Columbus.
The one thing that could hold Ohio State back from achieving its goal, though, is its defense.
Meyer and the Buckeyes will have to replace six starters in the front seven, including all four starters along the defensive line.
Ohio State's best player on the back end, redshirt sophomore cornerback Bradley Roby, is still pondering an early exit to the NFL. If Roby opts out of his junior season and enters the draft, it would be a devastating blow to the Buckeyes.
For now, Meyer has to worry about his defensive front.
Replacing All-Big Ten players like defensive end John Simon and defensive tackle Johnathan Hankins isn't something that's done with ease.
Simon, who Meyer called the heart and soul of the 2012 Buckeyes multiple times throughout the season, led the Big Ten with nine sacks on the season despite only playing in 11 games. Simon saved the best game of his career for last, tying a school record for sacks in a game with four against Wisconsin. The senior defensive end was rewarded for his outstanding season by winning the Big Ten's Defensive Player of the Year award.
Hankins anchored Ohio State's defensive line for two consecutive years, starting every game during his sophomore and junior seasons. The huge defensive tackle piled up 55 tackles, four tackles for a loss and one sack for the Buckeyes this year before opting out of his senior season and entering the NFL draft.
Losing Nathan Williams, Garrett Goebel, Etienne Sabino and makeshift linebacker Zach Boren to graduation is another tremendous blow to a unit that underperformed most of last season.
If Ohio State expects to win a national title next year, Meyer will need a number of young guys to step up and play beyond their years.
True sophomores like Noah Spence, Adolphus Washington and Tommy Schutt will see plenty of action in 2013. The trio of linemen were entrenched in Ohio State's defensive line rotation as freshmen, and it will be crucial to the Buckeyes' success for these guys to take a positive step forward.
Another infusion of freshmen talent should hit the trenches when Meyer's 2013 recruiting class makes it to Columbus. Guys like Joey Bosa, Michael Hill and Tracy Sprinkle will add depth to an already loaded group of linemen that includes juniors Michael Bennett and Joel Hale.
The linebacker position has to be Meyer's biggest concern. Arguably the team's best defender—Ryan Shazier—will be back for the Buckeyes, but no other linebacker on the roster has seen significant action.
Curtis Grant will likely get another crack at a starting spot after earning, then losing, the middle linebacker role at the beginning of the year.
A number of soon-to-be sophomores like Joshua Perry, David Perkins and Cam Williams will get a look as well.
Meyer is also after two of the top high school prospects in the country, Mike Mitchell and Trey Johnson. If Mitchell and Johnson commit, they would likely be in the fold as soon as they step foot on campus.
Meyer won two national championships during his tenure at Florida, and both of the those teams relied heavily on their defenses. If he wants to win it all at Ohio State, a number of young players will need to have breakout seasons in 2013.
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