Buffalo coach Nate Oats reacts to a play against Arizona during the second half of a first-round game in the NCAA men's college basketball tournament Thursday, March 15, 2018, in Boise, Idaho. Buffalo won 89-68. (Ted S. Warren)

A lot has happened to Nate Oats over the past few years.

He was head boys’ basketball coach at Romulus High School in suburban Detroit, became an assistant at Buffalo under Bobby Hurley, then took over the program when Hurley was hired by Arizona State three years ago. And, most importantly, while Buffalo posted winning records in each of his first three seasons and reached the NCAA tournament twice as Mid-American Conference tournament champion, Oats has been by his wife Crystal’s side as she fought through a bout with cancer.

So if you’re looking for Oats and the 13th-seeded Bulls to take themselves as seriously as many teams would in their position — entering a second-round South Region showdown with No. 5 seed Kentucky on Saturday — you’ll be wasting your time.

“I’m not going to overdo a game,” Oats said Friday afternoon. “At the end of the day, it’s a game. Now, we have a lot of fun with the game of basketball, and I don’t think anybody works harder than we do. Our guys get in the gym at night, and we make it a big deal to put the work in.

“But at the end of the day, let’s teach each other to be real men. We can use the game of basketball to teach each other a lot of life lessons that are much more applicable to things you’re going to have to do when you’re 30 and 40 than this.”

Oats did not concern himself with mincing words after Buffalo’s stunning 89-68 demolition of No. 4 seed Arizona here at Taco Bell Arena on Thursday night. Instead, he systematically broke down how Buffalo routed Arizona, a favorite to not only reach the Final Four but potentially win the national title.

Buffalo had better guards, he said. Arizona was not used to ball pressure and struggled to shoot three-pointers. The Bulls could limit the touches the Wildcats’ star center, DeAndre Ayton, would get in the paint.

Then, before his players left the podium, they had a message for former president Barack Obama — who had picked Arizona in his bracket.

“President Barack Obama, he picked Arizona to beat us,” junior guard C.J. Massinburg said. “And I just want to say, President Obama, I’m sorry, but I had to.”

Amid the laughter that followed, senior guard Wes Clark chimed in.

“Should have chose the handsome guys,” he said, earning even more laughs.

The truth is, though, that Buffalo (27-8) believed long before it handled Arizona. The MAC regular season and tournament champions didn’t arrive here this weekend expecting to have fun and go home after one game, or even two. They fully expected to arrive here and go toe-to-toe with Arizona and Kentucky — as blue blood as it gets in college basketball — and come out on top.

That’s why, when the idea that Buffalo had become this year’s Cinderella story came up Friday, Oats’s players immediately shot down the notion.

Why? They consider themselves to be every bit as good as the teams they are going up against.

“Everybody thinks we should be here,” guard Jeremy Harris said. “And yesterday’s game wasn’t, like, a fluke, or whatever you call it. But I think we have a very confident team. And I don’t really like the term ‘Cinderella team.’ ”

It’s a mentality that comes from the faith their coach instills in them.

“He’s the number one supporter of us,” said Clark, who played for Oats in high school at Romulus before going to Missouri and eventually transferring to Buffalo. “He’s the number one person that’s pushing the confidence. Not only have we been good, but we’ve never had a guy that is in tune as a player’s coach as Coach Oats.

“I want to say everybody in this room has had some sort of a slump at some point this season, and you can always count on Coach Oats to be there for us.”

That includes being willing to take the pressure off his players by putting the spotlight on himself. That’s exactly what Oats did by chastising Kentucky Coach John Calipari for his penchant for reminding everyone of the inexperience of his freshman-laden roster.

Though Oats went out of his way to praise Calipari’s coaching ability Friday, he didn’t back away from his point.

“It is what it is,” he said. “Their players are going to play in the NBA for a reason. There’s a reason that three of these guys are in the first round [of the NBA draft] . . . talent level is absolutely there. And, when they go win the lottery, I’m going to agree with NBA teams that took them. They’re that good.

“[But] they’re still freshmen. No disrespect to our two freshmen, [but] they have lapses. We’re experienced. They’re inexperienced. It’s no disrespect. It is what it is.

“It’s facts.”

Not surprisingly, Calipari — never one to shy away from a microphone himself — had his own thoughts on the matter.

“I don’t know if it’s whining or telling the truth,” he said. “I’m not whining about it. I’ve got a pretty good team.

“At the end of the day, we’ve got to play a basketball game. Everybody has got to get in the ring and play.”

Buffalo will get its shot at doing just that Saturday. And, if the Bulls can pull off the upset, they’ll be 40 minutes away from being a nationwide story for the next several days.

A moment like that could paralyze a team, and leave it too tight to play up to its usual standard. But when that team is Buffalo, and it spends every day utilizing the same approach no matter who it is playing — or where it is playing them — the last thing Oats expects is for his team to be overwhelmed by that moment when it arrives.

“No, we ain’t gonna be that,” he said. “Look, Wes is a killer, I love that kid to death. He’s going to think he’s the best kid on the floor. Jeremy Harris, he’s going to think he’s the best kid on the floor. [Nick] Perkins walked in as a freshman and was the leading scorer in the game against Miami. C.J. walked into Cameron Indoor as a freshman and dropped 17 and blocked Brandon Ingram.

“These kids all play like that. They ain’t scared of much.”

Neither is their coach.