The second part of our 2017 Summer Guide is position previews. For each position, we'll outline who's returning, who's gone and what the big question facing the unit is before finishing up with our projected depth chart.

The final installment in this series brings us to the cornerbacks, a position with two clear starters but little proven depth.

Overview

Returning starters (career starts): Montre Hartage (13) Keith Watkins II (2 in 2015, missed all of 2016 with leg injury)

Other returners: Marcus McShepard (1), Alonzo Mayo (1), Roderick Campbell Jr., Moe Almasri, Joe Bergin

Key losses: Trae Williams (hurt Achilles, out for at least first month of season)

Redshirt freshman: Brian Bullock

True freshman: Cameron Ruiz

In 2015, cornerback was one of the strongest position groups on a Northwestern defense that finished 4th in the country in S&P+. Nick VanHoose and Matt Harris were a lockdown tandem on the outside, making plays like this one and this one as the Wildcats sailed to a 10-3 record. Keith Watkins II was outstanding as a third corner in his sophomore season. VanHoose was a senior, but with Harris and Watkins coming back, and young players like Montre Hartage and Marcus McShepard underneath them, Northwestern appeared to be set at the position for 2016 and beyond.

Then...the football gods’ cruel sense of humor reared its head. Watkins was lost for the season with a knee injury in August. Harris suffered another concussion in Week 2, and made the decision to retire from football in October. Neither projected starter would see the field in Big Ten play, and as a result, youth was thrown into the fire. Hartage, McShepard, and redshirt freshman Trae Williams, 0 career starts to their name, became Northwestern’s top three corners. Unsurprisingly, it was an up-and-down ride.

Yet there is reason to be optimistic about the position heading into 2017. Watkins is back and finally has the opportunity to step into a No. 1 role. Hartage, who gained invaluable experience in starting all 13 games last season and flashed exciting potential at times, will start across from him, and the All-Big Ten Honorable Mention should be even better with another offseason under his belt. McShepard played a lot in 2016 and looks like a very capable third corner who will see the field a lot against 3-WR sets. Even though Williams (9 starts last season) will miss at least the first month of the season and probably more, that’s a very solid trio. In addition to that, Alonzo Mayo and Roderick Campbell Jr. provide young talent waiting in the wings.

Key Player: Keith Watkins II

When Keith Watkins II takes the field against Nevada, he will be doing so for the first time in 20 months. Watkins, whose last game action came in the Outback Bowl, is an immensely talented player. Pat Fitzgerald thinks he has NFL ability. Still, you can never be sure what to expect from a player coming off a major leg injury, especially a brutal non-contact ACL tear. Will that same explosiveness be there? Will he be hesitant at all? Cornerback is a position that requires rapid changes of direction, split-second decision making, and the athleticism to leave your feet and get a hand on the ball. It could easily take a while for Watkins to re-adjust to the speed of the game.

There are factors working in his favor, though. Watkins has the luxury of playing next to an experienced pair of safeties in Godwin Igwebuike and Kyle Queiro. Early on, Fitzgerald and DB coach Jerry Brown could elect to put Hartage on teams’ No. 1 receivers, which the junior proved himself capable of doing effectively last season. That would give Watkins time to get back into a rhythm and potentially earn that job back. But, if he is able to come back better than ever, Watkins could turn this secondary from good to great, or even great to elite.

Big Question: Will we see a repeat performance from Montre Hartage?

Hartage was one of the biggest surprises of the 2016 season, and has one of the better background stories of anyone on the roster. A former two-star recruit with one offer, Hartage was committed to Georgia Southern until a spot opened up late in Northwestern’s 2015 recruiting class. Fitzgerald offered him just days before signing day, but got it done. Hartage would skip the typical redshirt season and play in all 13 games on special teams as a true freshman. Last year, in his first real taste of playing cornerback at this level, Hartage surpassed everyone’s expectations. He recorded 60 tackles and led the team in both pass breakups (9) and interceptions (5). He was inconsistent, but considering the circumstances, fantastic.

So what’s in store for his encore? Now a junior, Hartage has a starting role locked up. If he can put together the dynamic man coverage and ball-hawking skills we saw last year for a full season, he could be one of the better corners in the conference. To put his INT total in perspective, the last players to have five picks in a season were Brian Peters in 2011 and Sherrick McManis in 2009.