Three questions facing Northwestern football this spring

Northwestern was the first team in the Big Ten to return to the practice field in 2016. With the Wildcats kicking off spring football this week, we take a look at what went well and what didn't last year then ahead at what types of things coach Pat Fitzgerald's team will likely be trying to improve.

2015 rewind: After back-to-back 5-7 seasons, the Wildcats bounced back with a 10-3 campaign in 2015.

They started it out with a stunning 10-6 victory at home over Stanford en route to a 5-0 start. Then came a 38-0 humbling by Michigan and a 40-10 blowout loss at home to Iowa, but Fitzgerald's crew finished the regular season on a five-game winning streak that included two-point wins over Nebraska and Penn State.

They beat Purdue by a touchdown and Wisconsin by six before topping Illinois 24-14. That got them into the Outback Bowl, where they were crushed by Tennessee 45-6.

With the worst offense in the Big Ten for the second season in a row, the Wildcats won with defense. They finished 23rd or better nationally in all the major defensive statistics, including 12th in scoring defense (18.6 points per game) and third in pass efficiency.

Offensively, few teams were worse passing but Northwestern had the No. 42 running game in the country (fourth in the Big Ten).

Biggest questions to answer:

1. Can the Wildcats improve the passing game?

Quarterback Clayton Thorson completed just over 50 percent of his passes (159 for 295) last season as a redshirt freshman.

He threw for 1,522 yards and ran for 397 behind an offensive line that allowed 29 sacks, but perhaps most importantly finished with more interceptions (nine) than touchdowns (seven).

Per InsideNU.com, Fitzgerald told reporters on the first day of spring practice this week Thorson is expected to remain the starter, but an effort to remake the receiving corps seems to be underway after starters Christian Jones and Miles Shuler were among those who ran out of eligibility.

The program announced three players have moved to receiver this spring -- former running back Solomon Vault and former defensive backs Marcus McShepard and Steven Reese.

Thorson's likely backup, Matt Alviti, is among the injured players expected to miss all of spring practice.

2. Can the offensive line take a step forward?

Northwestern was 12th in the Big Ten in sacks allowed last season, but the offensive line should come back mostly intact.

It could also get a boost from Ben Oxley, a former defensive lineman who has flipped sides of the ball.

Last year's starting right tackle, Eric Olson, is also among players who are out this spring.

Despite problems with pass protection, the offensive line was able to help sophomore tailback Justin Jackson run for 1,418 yards and five touchdowns last season.

3. Who will step up on the defensive line?

After combining for 26 tackles for loss and 12 sacks last season, Dean Lowry and Deonte Gibson must be replaced at defensive end.

Ifeadi Odenigbo would appear to be the top candidate to take the job of stud pass rusher after he logged five in reserve duty last year. The other backup, Xaiver Washington, had 3.5 tackles and a sack.

Listed at 250 and 240 pounds, respectively, both are smaller than Lowry (290) and Gibson (265), so it will be interesting to see if that effects a lineup that returns both starting tackles (C.J. Robbins and Tyler Lancaster).

Jordan Thompson, a 6-foot-3, 275-pounder listed as a backup defensive tackle last season as a true freshman, is a four-star talent who could force his way onto the field, too.