How's this for scary: The Gophers face Jim Harbaugh's 15th-ranked Michigan squad this Halloween night, three days after their catalyst coach, Jerry Kill, suddenly retired.

Even more frightening is the Gophers' next two: at No. 1 Ohio State and at No. 10 Iowa.

Welcome back to the sideline, Tracy Claeys. As the interim head coach begins the most important stretch of his professional life, hoping to prove himself worthy of becoming Kill's permanent replacement, his first three tests come against: the nation's top defense, the defending national champs and this season's surprise upstart.

Asked about this daunting stretch, Claeys smiled and said, "It's kind of like they say, 'How do you eat an elephant? One bite at a time.' "

The Gophers used this approach two years ago when Kill took a leave of absence to treat his epilepsy. Claeys stepped in as acting head coach, and the Gophers reeled off their first four-game Big Ten winning streak since 1973.

The Gophers were coming off lopsided losses to Iowa and Michigan when that streak started, so it was fully unexpected. A quick review:

• The Gophers were 12½-point underdogs at Northwestern and beat the Wildcats 20-17.

• The Gophers were 10-point underdogs against Nebraska and beat the Cornhuskers 34-23.

• The Gophers were nine-point underdogs at Indiana and beat the Hoosiers 42-39.

• The Gophers were 2½-point favorites against Penn State and beat the Nittany Lions 24-10.

Claeys served as acting head coach through the end of that season, but Kill was back at full capacity, coaching from the press box by the Nebraska game.

Now, the Gophers (4-3, 1-2 Big Ten) are trying to overcome the sadness of seeing Kill retire Wednesday for health reasons.

"I'd do anything for that guy," quarterback Mitch Leidner said. "He's done so much for me and my family, and I want to play as hard as I possibly can the rest of the season.

"Out there at practice, the way we rallied around each other for Coach Kill is unbelievable. You can just feel it in the air."

Claeys, who spent 21 years working for Kill, mostly as a defensive coordinator, said he never wanted a head coaching chance to come along like this. But that's what it is now — his chance.

The next month will be a proving ground for Claeys and the rest of a coaching staff that Kill assembled, with several assistants who've been together for 15-plus years.

Claeys said changes would be minimal under his direction — for now. He actually hinted at some offensive adjustments he might make if he gets to keep the job.

"I pretty much know on defense what I would like to do," he said. "[Offense] is the side of the ball that we would look at, and the philosophy of that, and find something that fits my personality and what I think can be successful again at the University of Minnesota.

"Right now, I don't have time to think about that. … The guys on offense … [have] got to find a way to get our best people the football in space and give them an opportunity to make a play … [and] take care of the football.

"Offense is pretty simple really — but I shouldn't say that. It's a simple idea that is extremely hard to execute. Those [offensive coaches] will work their tail end off, and they did the last time."

The Gophers rank last in the Big Ten in scoring offense, at 20.4 points per game. Two years ago, during that four-game conference winning streak, they found an offensive groove, with Philip Nelson leading the way at quarterback and David Cobb running strong.

The next month will bring a much steeper challenge for the offense. Even though the Gophers pulled some big upsets in that 2013 stretch, it didn't include any opponent that finished the season with a top-25 defense.

This year, the Gophers have four games remaining against teams currently ranked in the top 10 in scoring defense — Michigan (first), Wisconsin (second), Ohio State (ninth) and Iowa (10th).

Michigan (5-2, 2-1) looks reborn under Harbaugh, mostly because it leads the nation, by a wide margin, in total defense (210.6 yards per game) and third-down defense (.196 opponent conversion rate).

Like the Gophers, the Wolverines are coming off a bye week. Michigan's last game was a gut punch, as a muffed punt snap and last-second touchdown return gave Michigan State a 27-23 victory.

Still, it's clear Michigan has come a long way from the team that lost 30-14 to the Gophers last year in Ann Arbor.

"It's kind of like a book," Harbaugh said. "The prologue has been written, and now, if it's going to be a great book, then it's got to have one heck of a conclusion."

The Gophers have their own story to finish, and Claeys just emerged as a central character. Saturday will be emotional, with the Gophers planning a scoreboard tribute to Kill, who isn't expected to be in attendance.

"It's our obligation to be ready to go on Saturday," Claeys said. "That is one thing that this game teaches you — it's for tough people. And I believe that tough people get through tough times. So our kids will be just fine."