The most significant obstacle standing between the University of Wisconsin men’s basketball team and the Final Four is one of the best defenses in the country.

It’s a good thing the Badgers come equipped with a red-hot offense that has been one of the most efficient units in the nation this season.

That strength-on-strength matchup will go a long way in determining who advances to the national semifinals out of the NCAA tournament’s West regional when UW (29-7) plays Arizona (33-4) in the Elite Eight tonight at the Honda Center.

The Wildcats have the No. 1 defense nationally in adjusted defensive efficiency, according to KenPom.com, and Badgers assistant Gary Close certainly wasn’t about to dispute that ranking after putting together a scouting report on Arizona.

“I think it’s the best half-court defensive team we’ve played all year,” Close said. “I think they’re that good. The (Pac-12) is a high-scoring league, and they’ve been doing it against teams that like to score.

“You talk an awful lot about offensive talent, these guys have defensive talent. They’re quick, they’re long, they’re physical, they’re committed, they play hard, they’re well-coached, fundamentally sound.”

Arizona plays a pack-line defense under coach Sean Miller that is similar to the one UW rode to the Final Four under Dick Bennett and the one that helped make Tony Bennett and Virginia a No. 1 seed this year.

But Close said the Wildcats’ method is more aggressive than the Bennett version, which the Badgers saw up close when they survived a poor shooting game to beat the Cavaliers 48-38 in December.

“They’re more into you,” Close said. “Both teams are real good defensive teams, but I would say this team is a little more out getting after you and physically trying to impose their will.”

Junior guard T.J. McConnell said the Wildcats try to “pest guys into taking bad shots” — and they’ve accomplished that on a pretty consistent basis throughout the season.

Arizona has held its opponent under 40 percent from the field in 20 of 37 games this season. Defense has allowed the Wildcats to overcome an inconsistent offense and the loss of Brandon Ashley, the team’s third-leading scorer, to a season-ending foot injury in February.

“We kind of said in the beginning of the year, we wanted to be a top-five defense in the country, even the No. 1 defense in the country. And I think we’ve been No. 1 in the country for most of the year,” McConnell said. “We knew if we played defense, we’d win, it would lead to our offense and we’ve just done a good job of that all year.”

UW has played some of the finest defenses in the country this season with mixed results.

The Badgers, who are ranked No. 4 nationally in adjusted offensive efficiency, averaged less than a point per possession in games against Florida, Virginia, Saint Louis and Northwestern. Those teams are ranked No. 2, 5, 7 and 14 in adjusted defensive efficiency. The Badgers averaged 1.02 points per possession during a home loss to Ohio State, which is No. 4.

On the flip side, Illinois’ defense is ranked No. 11 and the Badgers averaged 1.36 and 1.25 points per possession in a pair of victories over the Fighting Illini.