The Nebraska Cornhuskers did a pretty major overhaul in the offseason. That’s to be expected on the heels of a 4-8 season (.333), which represented the program’s worst winning percentage since a 3-7 mark in 1958.

Mike Riley had two losing seasons in his three-year tenure as Nebraska coach, an unforgivable sin in Lincoln.

So entering 2018, Nebraska has a new head coach (Scott Frost) and new coordinators on offense (Troy Walters) and defense (Erik Chinander). There are a lot of new ideas to shake out including an up-tempo offense which Frost, a former quarterback at Nebraska, used to great effect as UCF’s coach last season — the Knights went 13-0 and won the Peach Bowl.

Nebraska goes back to the drawing board at quarterback, with no returner having thrown a pass in college. But while the QB derby steals the headlines, other position battle rage as the season nears.

Here are the 3 most important ones.

Running back

Nebraska ranked 13th in the Big Ten and 120th in the nation in rushing last season at 107.5 yards a game.

Summary: It is an understatement to say there is a logjam at this position. Juniors Greg Bell and Tre Bryant are favorites to get the bulk of the playing time, and Devine Ozigbo is the team’s leading returning rusher.

Why it’s important: For all the talk of how much up-tempo, spread offenses pass the ball, an underappreciated aspect of that style is the importance of running the ball well. Two of Nebraska’s top 10 recruits in the Class of 2018 were running backs including Maurice Washington, who is already grabbing attention early in fall camp. Frost’s UCF team averaged nearly 200 rushing yards per game in 2017 to rank 32nd in the FBS.

Linebacker

Summary: Luke Gifford and Dedrick Young return, but this bunch is mostly inexperienced. Junior Tyrin Ferguson has turned heads in practice and true freshman Caleb Tannor is jockeying for immediate playing time.

Why it’s important: Nebraska was gashed frequently by opposing running backs in 2017. According to Athlon’s, opponents gained at least 5 yards on 46.8 percent of their carries against the Cornhuskers, the second-highest percentage allowed among 130 FBS defenses. On a unit with a lot of holes — the once-fabled “Blackshirts” finished last in the Big Ten in total defense in 2017 — the linebackers need to step up because the veteran line should at least be decent.

Secondary

Summary: Safety Aaron Williams and cornerback Lamar Jackson return to a unit which allowed 221.6 passing yards per game in 2017. Nebraska signed two safeties among its top 10 recruits in the Class of 2018 and the veterans know they are under fire.

Why it’s important: Secondary coach Travis Fisher is on the record as saying that last season’s Cornhuskers backline played too soft. Part of Nebraska’s many defensive woes in 2017 was that the D didn’t give the offense enough easy chances; the Cornhuskers were 114th in the country in forcing turnovers at 1.0 per game. As often as teams pass now, that’s just not good enough.