MANHATTAN — Just what is the shelf life for a wave of momentum?

If it exceeds eight months, Kansas State football could be in for something special in 2018.

Rebounding from a 3-4 start last year, the Wildcats caught fire in the second half, winning five of six games to not only gain postseason eligibility but also top it off with a 35-17 come-from-behind victory over UCLA in the Cactus Bowl.

Their offense returns nine starters at eight positions, including all five linemen and power running back Alex Barnes, after ranking second in the league in rushing. A down-to-the-wire quarterback battle adds to the intrigue, but the Wildcats have a legitimate All-America candidate at right tackle in senior Dalton Risner.

There are more questions on a defense that brings back just five starters after ranking 91st overall and second-to-last among the nation’s 129 FBS teams against the pass. Senior safety Kendall Adams, who missed the end of last season and all of spring practice with an injury, is healthy again and was a preseason all-conference by Big 12 media.

Meanwhile, hall-of-fame coach Bill Snyder keeps on ticking at age 78, signing a five-year contract earlier this month. But there were a couple of major changes to his staff, where Andre Coleman was promoted to offensive coordinator when Dana Dimel took the head coaching job at Texas-El Paso and Blake Seiler took over for the retired Tom Hayes as defensive coordinator.

To help break down just how things will shake out, here are two key questions, players and matchups for the 2018 Wildcats:

TWO QUESTIONS

1. Who will start at quarterback?

Junior Alex Delton and sophomore Skylar Thompson each made four starts last year after senior Jesse Ertz’s season ended with an injury in Game 5 at Texas.

Though both had moments of brilliance — Thompson excelled in victories over Oklahoma State and Iowa State while Delton came off the bench to claim offensive MVP honors in the Cactus Bowl — neither was able to claim the job in the spring, extending the competition to preseason camp.

Delton is widely considered the stronger runner and Thompson the more accomplished passer, but their skill sets are similar enough that consistency over the past month most likely will be the determining factor.

“Both are very deserving,” Coleman said. “And they both are going to help us win this year.”

2. How will new coordinators impact the offense and defense?

Coleman, 45, and Seiler, 34, both played under Snyder before joining his coaching staff, and remain committed to the system.

But players on both sides of the ball have commented on the energy and passion they bring to their new positions. And Coleman especially has expressed his desire to delve deep into Snyder’s legendary playbook.

“I want to find ways to put our best players on the field and find ways to get them all the ball,” he said. “That’s what excites me.”

Seiler said the ability to adapt and think on his feet is paramount in a league known for its prolific offenses.

“I don’t think you can put a price on adjusting fast,” he said. “Because you’re going to study what they’ve shown all week long, you’re going to practice that all week long (and) then they’re going to show up and those first two series you’re guaranteed you’re going to see two or three things that you haven’t worked on.”

TWO PLAYERS

1. Junior running back Alex Barnes

All signs point to a breakout season for Barnes, a powerfully built 6-foot-1, 225-pounder who burst on the scene as a redshirt freshman by rushing for 442 yards in 11 games with an incredible 7.9 yards per carry.

Starting all 13 games last year, Barnes led the Wildcats with 819 yards and became the second-fastest in school history to reach 1,000 career yards behind only Darren Sproles. But his 5.6-yard average per attempt was viewed by some as a disappointment.

Barnes has drawn praise from Snyder in preseason and has dedicated himself to getting in maximum shape in the weight room and through his eating habits. Combine that with a veteran line and a pair of nimble quarterbacks to deflect the pressure and all the pieces are in place.

2. Junior defensive end Reggie Walker

Walker, by the standard he set as a redshirt freshman two years ago, had a disappointing sophomore season with 36 tackles and two sacks in 12 starts after totaling 39 stops with 11.5 for loss and 6.5 sacks in 2017.

But he no longer had All-American Jordan Willis on the other side to occupy offensive linemen’s attention, plus both Seiler and Walker admitted that nagging injuries took a toll. Given K-State’s poor showing against the pass in a league known for airing it out, Walker said the defensive line has made it a priority to improve on last year’s 24 sacks and ease the burden on the secondary.

TWO MATCHUPS

1. vs. Mississippi State (11 a.m. Sept. 8)

Beating the preseason No. 18-ranked Bulldogs in Week 2 not only could vault K-State into the Top 25, but provide a signature victory that sets the tone for a whole season.

Mississippi State, coming off a 9-4 season and picked third behind Alabama and Auburn in the rugged SEC West, has a new coach in former Penn State offensive coordinator Joe Moorhead. Moorhead, who previously was 38-12 in four years as head coach at Fordham, is considered an offensive innovator, but the Bulldogs’ strength should be a defense that returns eight starters after ranking 10th nationally last year in fewest yards allowed.

2. at West Virginia (Sept 22)

This Week 4 test against the preseason No. 17 Mountaineers is just as pivotal, regardless of the Mississippi State outcome. It’s the Big 12 opener and the first road game.

Pair it with a victory over Mississippi State and the sky’s the limit for the Wildcats. If they lose to the Bulldogs, they’ll need it to recalibrate quickly heading into the conference season.

West Virginia is picked second in the Big 12 behind Oklahoma and features a Heisman Trophy candidate in quarterback Will Grier, plus preseason all-conference picks in receiver David Sills, offensive lineman Yodny Cajuste and linebacker David Long.