Big Ten looking to fill holes on defense, add depth on signing day

As national signing day approaches, here's a look at each Big Ten team's biggest needs.

Illinois Fighting Illini

Illinois must replace the heart of its defense, middle linebacker J Leman. The Illini lose another standout linebacker, Antonio Steele, but there's more depth at outside linebacker than there is in the middle. The defensive backfield also could use a boost after the graduations of Kevin Mitchell, Justin Harrison and Justin Sanders, each of whom ranked among the team's top seven tacklers last season. The departure of Big Ten Offensive Player of the Year Rashard Mendenhall to the NFL thins the depth chart at running back.

Indiana Hoosiers

James Hardy's size and production are almost impossible to replace, but Indiana can fill the cavity by beefing up at wide receiver. The Hoosiers already boast several solid targets for quarterback Kellen Lewis, and a few impact freshmen will help the Big Ten's third-highest-scoring offense. Despite Lewis' pocket mobility, the running game remains iffy and could use a fresh set of legs alongside Marcus Thigpen. Indiana ranked ninth in the league in pass defense last season and loses superstar cornerback Tracy Porter, making the defensive backfield a major need.

Iowa Hawkeyes

As coach Kirk Ferentz waits for the heralded recruits already on his roster to heal or blossom, he must build depth at several positions. Iowa loses standout linebackers Mike Humpal and Mike Klinkenborg, who combined for 202 tackles last season. Also gone is Bryan Mattison, who ranked sixth in the league in sacks (nine), along with fellow defensive end Kenny Iwebema. The offensive backfield likely will be addressed in this recruiting class, as lingering uncertainty at quarterback and the loss of running backs Albert Young (968 rushing yards) and Damian Sims (499 yards) raise red flags.

Michigan Wolverines

The obvious need here is a do-it-all quarterback who can effectively operate in Rich Rodriguez's explosive spread offense. With the durable Mike Hart gone, the Wolverines also could use another capable running back, as well as wide receivers to replace Mario Manningham and Adrian Arrington. But nothing else will matter if no one is around to block. Offensive line is a critical area for Michigan, which loses left tackle Jake Long and center Adam Kraus. The middle of the defense is also thin after the graduation losses of linebackers Shawn Crable and Chris Graham, both of whom recorded 90 tackles last season.

Michigan State Spartans

Wide receiver has vaulted to the top of Mark Dantonio's wish list after Devin Thomas declared for the NFL draft. In addition to Thomas, who led the Big Ten in all-purpose yards (2,590), the Spartans lose tight end Kellen Davis (513 yards, 6 TDs). With running tank Jehuu Caulcrick gone and Javon Ringer entering his senior season, Dantonio would be well served to add to the running back group. The offensive line also needs to be replenished after the loss of three starters, and safety has been thinned a bit by graduation.

Minnesota Golden Gophers

Highly regarded recruiter Tim Brewster tries to fill a variety of needs with his first true class as Golden Gophers coach. The nation's worst defense last season (518.7 yards per game) needs major upgrades at linebacker and in the secondary. Several seniors return at linebacker, but the Gophers could use a young playmaker. Quarterback Adam Weber showed tremendous potential but needs more weapons at wide receiver after losing Ernie Wheelwright. Depth is also a concern at running back after the loss of Amir Pinnix.

Northwestern Wildcats

Offensive skill players abound for the Wildcats, but so do questions up front. After an inconsistent season, Northwestern loses three starters from its offensive line, including center Trevor Rees. The reserves have yet to show much, and coach Pat Fitzgerald might need a freshman to step in right away. New defensive coordinator Mike Hankwitz could use immediate help in the secondary, where Northwestern has struggled for years. The Wildcats also need to find their next standout middle linebacker after the graduation of Adam Kadela.

Ohio State Buckeyes

Ohio State
The Buckeyes have to brace the edge of their offensive line after losing standout right tackle Kirk Barton. Alex Boone is back on the opposite side, but will need to be replaced in 2009. Ohio State also needs a successor for senior quarterback Todd Boeckman. Though the team once again should boast one of the nation's top linebacker groups in 2008, the impending departures of James Laurinaitis and Marcus Freeman requires attention. A top-of-the-line tight end could immediately enhance a passing attack that returns the Brians (Robiskie and Hartline) at wide receiver.

Penn State Nittany Lions

Linebacker U needs a few more 'backers to solidify its defensive midsection after losing star Dan Connor (145 tackles). Sean Lee returns for his senior season, but the Nittany Lions must build depth around him. Wide receivers Derrick Williams, Deon Butler and Jordan Norwood all will be seniors this fall, so adding a few prospects on the edge might be wise. Depth at offensive tackle will soon become critical for Penn State, which loses Gerald Cadogan after the season. The loss of Rodney Kinlaw hurts, so an addition at running back will help.

Purdue Boilermakers

The passing game is always paramount at Purdue, and this year should be no different in recruiting. Productive quarterback Curtis Painter is back, but he will need some new targets. The Boilermakers lose star wideout/return man Dorien Bryant, receiver Selwyn Lymon (dismissed from the team) and productive tight end Dustin Keller. Both positions must be addressed in recruiting. The offensive line is down two starters, and several others depart after the 2008 season. Purdue's defense needs bodies after the departures of end Cliff Avril (15 tackles for loss), cornerback Terrell Vinson, safety Justin Scott and linebacker Josh Ferguson.

Wisconsin Badgers

A defensive decline will be addressed in this class, as coach Bret Bielema tries to restore the unit to the top of the Big Ten. Wisconsin must add depth at defensive end and restore a pass rush that generated only 28 sacks last season. The linebackers look solid but a young secondary could be beefed up. Special teams are also a recruiting priority after the losses of kicker Taylor Mehlhaff (21-for-25 on field goals) and punter Ken DeBauche (41.6 yards per punt).

Adam Rittenberg is a college football writer for ESPN.com. You can contact him at espnritt@gmail.com.