Without J.T. Barrett, Ohio State's Championship Hopes Rest with the Defense

After J.T. Barrett suffered a season-ending ankle injury against Michigan, Ohio State's national championship hopes were ripped from the steady hands of the its budding quarterback and placed squarely on a defense that has slumped in recent weeks.

With No. 13 Wisconsin and its powerful rushing attack looming, the fifth-ranked Buckeyes will need that unit to step up in a big way to earn their first Big Ten title since 2009.

That development would have been hard to fathom at the beginning of the season.

When Ohio State lost its first option at quarterback after Braxton Miller re-injured his shoulder in fall camp, head coach Urban Meyer expected his defense to rally—fueled by what USA Today (h/t 247Sports) thought was the best defensive line in the country.

In fact, Meyer went as far as comparing this Buckeyes defensive front to one of the all-time greats—his former outfit at Florida that guided the Gators to a national title in 2006.

"2006 was our best defensive line at Florida. This line, if they all stay healthy and perform, could be on that level," Meyer told reporters. "We have some game-changers up front."

The Buckeyes certainly have game-changers.

Defensive end Joey Bosa has grown into one of the most disruptive pass-rushers in the country, leading the Big Ten and ranking fourth nationally with 13.5 sacks. The true sophomore was named the Big Ten Defensive Player of the Year and is a finalist for the Lombardi and Bednarik Awards.

Ann Heisenfelt/Associated Press/Associated Press

Ohio State has also gotten solid play out of defensive tackles Michael Bennett, who was named to the All-Big Ten Football second team, and Adolphus Washington, who earned an honorable mention from the media.

But the Buckeyes have greatly missed Noah Spence—their star junior defensive end who was supposed to balance the line opposite Bosa. Spence didn't play a snap all season thanks to a second failed drug test that resulted in a permanent ban from the Big Ten.

That, combined with a surprising lack of depth, has Ohio State's defensive line falling incredibly short of its preseason potential.

Over the last four weeks, opposing running backs have taken advantage.

It started on the road against Michigan State, when Jeremy Langford ripped Ohio State for 137 yards and three touchdowns on just 18 carries.

That triggered a bad trend for the Buckeyes, who have given up a combined 584 yards and 11 touchdowns on the ground to the last four running backs they've faced.

Player	Rush YDS	YPC	TD
Jeremy Langford	137	7.6	3
David Cobb	145	5.4	3
Tevin Coleman	228	8.4	3
Drake Johnson	74	4.9	2

On Saturday in Indianapolis, with a Big Ten title hanging in the balance, Ohio State will have to stop the nation's most dangerous running back. Wisconsin's Melvin Gordon, who leads the country in both rushing yards (2,260) and rushing touchdowns (26), has a blend of speed and toughness that could hurt the Buckeyes where they're the weakest.

Ohio State is hoping its recent run against elite ball-carriers can serve as preparation for what lies ahead.

“I mean we’ve seen a lot of good backs this year,” Buckeyes linebacker Joshua Perry told Austin Ward of ESPN.com. “Obviously [Gordon] is a Heisman front-runner, so he’s on a level of his own. But you can’t say that we haven’t been tested already with some of the running backs, some of the offensive lines we’ve seen this year."

The Buckeyes' improved secondary won't be tested much—the Badgers average just 147.8 passing yards per game, which ranks 117th out of 125 teams in the country.

But with Gordon in the opposing backfield, Bill Rabinowitz of the Columbus Dispatch reports Meyer is wary of the potential opportunities for play action:

Will the Buckeyes be able to stop Gordon and Wisconsin's ground attack?

Without its star quarterback as a safety net, Ohio State's Big Ten title hopes—and by extension, its playoff aspirations—will depend on it.

All stats via NCAA.com.

David Regimbal covers Ohio State football for Bleacher Report. Follow him on Twitter @davidreg412.