DURHAM, N.C. — Within Manny Diaz’s new office here at Duke University, a commemorative football sits emblazoned with the score of a football game:

Duke 45.

Miami 21.

On Oct. 22, 2022, 10 months after the Miami Hurricanes fired Diaz as coach, the Duke Blue Devils beat them in a stunner at Hard Rock Stadium. Diaz wasn’t a part of either program then. In fact, he was on the staff at Penn State.

And, yet, that football sits in his new office.

It makes little sense until the backstory is revealed. Duke’s current strength coach, David Feeley, was on the staff that beat the Hurricanes in 2022. He gifted the football to Diaz with, perhaps, an understood meaning: We won that one for you.

Almost exactly two years later, Diaz is five games into his second chance as a head coach and hasn’t yet lost.

The Blue Devils are 5-0 for the first time in 30 years, are two wins shy of a school record-tying nine-game win streak and are — somehow — not ranked in the Top 25.

That’s only the half of it. Diaz’s team did not receive a single vote in the poll.

“It doesn’t matter,” Diaz said Tuesday in an interview with Yahoo Sports. “Nobody remembers who was ranked after Week 5 a year ago. We didn’t get to be 5-0 by valuing that.”

Their absence from the rankings is with reason. Few, if anyone, expected them here.

The fact that Duke is one of the 19 remaining undefeated teams in the Football Bowl Subdivision is one of the sport’s stunners a month into the college football season, right up there with unbeatens Army, Navy, UNLV, Indiana and Rutgers.

After all, Duke has a new coach (Diaz), a mostly new staff, a new quarterback (former Texas backup Maalik Murphy) and an almost completely rebuilt defensive front. Maybe most surprising of all: This team practiced with five healthy offensive linemen in the spring and now it’s a unit that has emerged as a bright spot with eight linemen transfers this offseason.

It was no easy chore reaching this point, of course. The Blue Devils trailed in the fourth quarter in three of those five wins. They needed a last-gasp, tying field goal against Northwestern just to send it to overtime; they were down by four to UConn before a 56-yard, lead-taking touchdown drive; and, most recently, they stormed back from a 20-0 deficit to stun rival North Carolina, 21-20.

Comeback Kids? More like Sewer Rats.

The program’s motto — drag opponents into the sewer — is derived from Feeley’s offseason conditioning program of fighting until the bitter end with grit, getting nasty at times and pushing the opponent for four quarters. Duke has outscored opponents 40-6 in the fourth quarter this season.

“Guys believe we get stronger as the game goes on,” Diaz said. “There is a belief in that.”

There is belief, too, in Diaz, a 50-year-old who landed his dream job (Miami in 2019), was unceremoniously fired from that dream job (after three seasons), returned as a defensive coordinator (at Penn State) and is now back in the big chair.

Duke athletic director Nina King hired Diaz after Mike Elko left for Texas A&M.

“I talked to a lot of people at Miami,” King said. “I felt I had a good understanding of what went on there. I thought, ‘Let’s give him a chance.’”

So, what exactly went on at Miami?

Diaz finished with 21 wins and 15 losses, never had a losing record in conference play and, he believes, fielded a team in 2020 that would have won 11 games (not eight) had the Hurricanes played a traditional schedule and not a COVID-altered slate.

The ending played out publicly. In his final season, the Hurricanes won five of their last six games, ending the year with, as it turns out, a 47-10 win at Duke. The late-season run did nothing to quiet the speculation over Diaz’s job status and the intention of the school to pursue Oregon coach and former Miami lineman Mario Cristobal.

After that final game over Duke, Diaz and staff began recruiting. For a week, as they traveled around visiting with players, the speculation continued, and the school — then without an athletic director — made no public statement supporting its coach.

His message to the staff then: We’re not out of it until they tell us.

“You’ve got to continue to press forward,” he said.

It wasn’t easy.

“There was a state of unsettlement,” said Feeley, who was Diaz’s strength coach at UM before moving to Duke to join Elko in 2022. “Guys were a little nervous. They knew something was wrong. Everybody knew it. That was pretty tough.”

The late-season run had enlivened Diaz. His team didn’t give up. The locker room began to bond. Things were coming together.

He’s been searching for that feeling ever since he was fired.

“When the plug gets pulled on that, you have an eagerness to try to recapture that,” Diaz said.

He was hurt enough by the firing that Diaz moved to Pennsylvania to join Penn State as defensive coordinator, a move that he describes as “geographically far from Miami, but also as far away as you can be in every way, shape or form.”

He calls his time with coach James Franklin a “reset” and a “recharge,” and he was afforded the ability to be “choosy” when head coaching jobs came open. He turned down interest in several jobs, including one back in his home state (South Florida).

It was too soon to go back down there, he thought, and surely, there will be a better option, right? “I never doubted that,” he said.

But why Duke?

The connections started with Feeley, a person that King leaned on for advice. After all, he spent all three seasons with Diaz at Miami. He knew him well.

Separately, Diaz’s own son, Manny III, applied to Duke for college well before the interview process. A week after Diaz’s hire, Manny III was accepted and he’s now a freshman.

But for Manny Diaz, there was something even more important in making this decision. In the evolving landscape of college athletics, would Duke invest enough to win and be included in whatever iteration is ahead for college football?

“I straight up asked President (Vincent) Price in a one-on-one interview,” Diaz said. “What if this happens and that … is Duke committed to stay at the highest level of college athletics? He looked me dead in the eye, ‘Duke is absolutely committed to compete at the highest level of football.’’

That’s echoed too by King.

“We do not want to be left out. We feel like we are putting in the investment, whether resources or people or facilities, etc.,” King said. “We want to make sure our program is in the next iteration, whatever it is. We are in a good position right now. Not sure you could have said that 5-10 years ago. We will be attractive. We’ll be able to go in with that next group of schools, whoever they are and break off.”

That doesn’t mean King isn’t anxious about the future.

As one of the country’s elite academic private schools, Duke’s tuition is as much as four times the cost of its public school competitors. That’s a financial disadvantage for an athletic department charged with funding the majority of those scholarships.

A full scholarship at Duke is about $90,000, King said. For comparison’s sake, in-state tuition at Clemson is about $16,000.

Like most administrators, King and her administrative staff have working models for possible athlete employment and/or athlete revenue sharing. These concepts could soon become a reality.

What then? Many schools don’t have enough revenue through ticket sales, donations and television money to fund a broad-based athletic department.

“It gives me anxiety,” she said. “What if football, men’s basketball and a few others are our only sports? We’ve cried wolf a lot in the NCAA, but I really do think the financial challenges … we are coming to a head soon.”

In the meantime, on the field, the Blue Devils continue to prove they belong. Duke is on the way to a third consecutive winning season for just the second time since 1960-62.

They can move closer to that Saturday, when Diaz and the Blue Devils meet Georgia Tech (3-2) in Atlanta. Games against Florida State and SMU follow before a Nov. 2 game at … Miami. The Hurricanes, like the Blue Devils, are undefeated but find themselves, unlike the Blue Devils, ranked No. 7 nationally.

It’s true. Diaz’s old team and Diaz’s new team could meet in Diaz’s hometown as unbeatens almost exactly two years after the date on that commemorative football resting in his new office.

Perhaps that would be too perfect.