With the 2017 recruiting classes in the books and spring practice just around the corner, we're taking a look at how the Big Ten teams stack up at each position group.

Hey, it's still early February, so things can change a lot between now and Labor Day weekend. Who saw Trace McSorley as arguably the best Big Ten quarterback this time a year ago? Or Austin Carr as the league's top receiver in 2016?

Young players and new faces will no doubt step in and surprise us. So we're basing a lot of this off returning experience. And because it's by position group, depth matters as well as star power.

Wrapping up on the defensive side of the ball, the defensive backs are next.

Kieron Williams (26) and Joshua Kalu (10) both return for a Nebraska secondary that should be the most experienced in the Big Ten in 2017. John S. Peterson/Icon Sportswire

Best of the best: Northwestern and Nebraska

The Nebraska coaching staff has undergone some changes this offseason, and pitching the opportunity to work with a staggering amount of experienced talent in the secondary was surely appealing when Mike Riley went out looking for new defensive assistants. With Kieron Williams, Aaron Williams and Chris Jones combining for 11 interceptions last season and Joshua Kalu in the fold as well, the Huskers have depth and stability in the secondary that few teams can match -- even with Nathan Gerry no longer in the program.

The Wildcats aren’t far behind thanks to Godwin Igwebuike ’s decision to return for another season, spurning the NFL draft to try to boost his stock after racking up 108 tackles with a pair of interceptions last year. Northwestern also heads into the offseason with an established unit of defensive backs, with Kyle Queiro returning at safety, Montre Hartage coming off a five-interception campaign and Trae Williams rounding out the group.

Runners-up: Indiana and Ohio State

The Hoosiers certainly haven’t been known for their defense during the last few years, but they’ve done a much better job addressing that side of the ball on the recruiting trail recently and it’s paying dividends with the personnel on hand for new head coach Tom Allen. Rashard Fant ’s decision to stick around for another year after leading the Big Ten in passes defended was a huge bonus for Indiana, and the Hoosiers will have four defensive backs who defended at least 10 passes last season back this fall.

The Buckeyes are something of a gamble here because safety Damon Webb and cornerback Denzel Ward are the only two returners with starting experience. But the banner recruiting classes in the secondary and the uncanny ability Ohio State has shown over the last few years to simply reload after losing multiple players early to the draft makes it a relatively safe bet to include them among the league’s best without even knowing who will round out the lineup. Defensive coordinator Greg Schiano and cornerbacks coach Kerry Coombs have no shortage of former four-star and five-star recruits to choose from, and by the end of the year, Ohio State could easily find itself back on top of the Big Ten.

Team that could surprise: Wisconsin

The Badgers have a pair of solid building blocks to work with in the back end, with cornerback Derrick Tindal and safety D'Cota Dixon giving new defensive coordinator Jim Leonhard a nice head start. But there’s work to be done with veterans Leo Musso and Sojourn Shelton no longer around after strong senior seasons, though Lubern Figaro has started 11 games during his career and could help the Badgers again emerge as one of the league’s best units.

Teams that need to step up: Michigan State and Rutgers

Given the track records of the two coaches, last season will easily qualify as unacceptable in the eyes of Mark Dantonio and Chris Ash. For Dantonio, the Spartans' struggles might have come as a surprise, but there’s no shame in a transition year after the wildly successful seasons that came before it. Dantonio should be able to get Michigan State back on track and improve on a defense that ranked 12th in the league in pass-efficiency defense and had eight interceptions.

The Scarlet Knights are facing a more difficult rebuild under Ash, and while his team allowed just 187 yards per game through the air, that’s thanks in large part to being on the wrong end of blowouts last season. Rutgers finished No. 13 in the league in pass-efficiency defense and also finished with just eight interceptions, leaving plenty of room for improvement.