Dave Wannstedt was scheduled for an interview with the News on Friday. But at the last minute, the Bills defensive coordinator backed out. Through a PR man, Wannstedt said he would prefer to talk Monday. This presumes, of course, that he still has a job by then.

So this sorry season has come full circle. We’re back where we were in the opener, with Wannstedt unable to provide any answers.

Evidently, it’s OK for the players to stand and take the heat for the defense’s failures. But the guy in charge of this defense feels no need to defend himself. The same goes for general manager Buddy Nix, who bailed on his radio show Friday.

And what would they say, anyway? How could Nix or Wannstedt – or head coach Chan Gailey – put a positive spin on the Buffalo defense, which has strung together the worst three-year run in the history of the franchise?

The Bills have allowed 426 points, which puts them 31st in the NFL. A year ago, they gave up 434 points, ranking 30th. In 2010, it was 425 points surrendered, good for 28th. I’m no Lombardi, but this is not my definition of progress.

In fact, Gailey’s three years as head coach would rank as three of the four worst in franchise history in terms of points allowed. The team record for defensive futility is 454 points, established by the 1984 squad that finished 2-14 under Kay Stephenson.

Maybe that’s why Wannstedt couldn’t find time to talk. No doubt, he was busy concocting schemes for keeping Mark Sanchez and the Jets under 30 points today, sparing the Bills the indignity of breaking the team record for points allowed in a season.

It’s sad to think it has come to this. A season that began with such promise, with fans’ hopes soaring after the signings of Mario Williams and Mark Anderson, will conclude with a whimper, with the Bills hoping to avoid an historic defensive embarrassment in a half-empty stadium.

Back in the summer, you figured the finale might mean something for the first time in eight years. The Bills had a $100 million pass rusher in Mario Williams. Anderson gave them depth on the line.

Kyle Williams was healthy.

This new, improved defense would terrorize opposing quarterbacks, make the secondary better, create turnovers and give the offense prime field position. Ryan Fitzpatrick wouldn’t have to win games with his arm. It would be enough for Fitz to be average, to manage the games.

The schedule looked soft. It was loaded with first- and second-year quarterbacks, with a crossover against the perennially weak NFC West. Miami was a joke. Sure, the Patriots were the class of the division. But in all likelihood, one of the wild cards would come out of the AFC East.

So three months ago, you assumed today’s game might be for a playoff spot. Considering that it was a down year in the AFC, maybe both the Bills and Jets would qualify for the playoffs!

Instead, both teams are out of it, their programs in turmoil.

Gailey will likely lose his job. Wannstedt, who inherited the coordinator job when George Edwards took the fall a year ago, is almost surely gone.

Fitzpatrick has probably played his last game as a Bill.

Despite reaching the AFC title game in his first two seasons (2009-10), Jets coach Rex Ryan is under fire, compromised by the Tim Tebow fiasco. GM Mike Tannenbaum is expected to be pushed out, perhaps moved back to a job managing the salary cap. The standard is high in other NFL cities, after all. It’s hard to imagine Nix surviving anywhere else.

Sanchez is expected to start his final game as the Jets’ quarterback. Sanchez, the one-time franchise hope, had lost his starting job after a nightmare of a season, but will be momentarily restored to the No. 1 job because of an injury to Greg McElroy.

It’s fitting that Sanchez would be the man today. He was the guy who started Wannstedt’s defense on a quick downward spiral, playing one of the finest games of his four-year career in the Jets’ 48-28 home victory over the Bills in the opener.

That game seems even more stunning in retrospect. It’s not so much that the vaunted Bills’ defense fell in its first game with Mario Williams (who whined about the replacement officials afterwards), but that Sanchez could look so good in a season that would quickly go to pieces.

The Jets scored 48 points in the opener. In their next 14 games, they averaged 16.0. Precisely one-third as many. They’ve scored 20 points only four other times. The offense turned into the joke of the league, Sanchez a dart board for derision in New York.

But for one day, the Buffalo defense made Sanchez look like Joe Namath. Given an entire offseason and a $100 million player, Wannstedt played soft. He had his corners playing off and allowed Sanchez to pick him apart. The guy froze, assuming his four-man pass rush would save the day.

The defense had its moments later in the season, mostly against inferior offenses. But it never got much better after that Jets game. Wannstedt, who built his reputation with a studded roster in Dallas two decades ago, had few answers. He coached like a man who felt it was 1992, not 2012.

Wannstedt was too reliant on his front four. The linebackers were bad, yes, but the situation begged for an inventive mind. Wannstedt wasn’t up to it. He had few creative ways to rush the passer. His defensive players spent the year talking about “run fits,” making it sound as if their coach couldn’t get everyone on the same page.

Gailey, who had enough problems with his offense and game management, washed his hands of the defense. But it’s his failure, too. He botched the defense from the start. It’s also on Nix. He hired Gailey. He signed off on George Edwards, and then on Wannstedt.

Before he leaves, Wannstedt could provide one last service for the organization. Bring back the same defensive game plan he used in the opener.

Play soft and let Sanchez go out in a blaze of glory. With luck, the Jets will use Tebow, too. Then the Bills could remind us how well they defend the read option. Giving up 30 points should be a snap.

There’s a lot at stake here. Losing today could be the difference between picking fourth and 10th in the draft. Come on, guys. After three years of messing up the defense, you have one last chance to get it right.