INDIANAPOLIS – When he was hired as the Illinois basketball coach, Brad Underwood made the trip to Champaign alone.

Well, there was family, but Underwood came here with no coaching staff in tow. If he was to get this program turned around, Underwood would be doing it with a group of assistant coaches who would be new it him.

It was a red flag for some guys in the coaching industry, who thought it unusual not one guy would join Underwood, other than support staff. But the former head coach at Oklahoma State and Stephen F. Austin calmly completed his homework, made his phone calls and did the due diligence in building his staff.

The two most key pieces are still here. When Underwood hired Orlando Antigua and Chin Coleman, he secured two building blocks. In years to come, folks will ask, How were the Illini built? The foundational pieces weren’t superstar Ayo Dosunmu or big man Kofi Cockburn.

MORE: King Kofi a match-up problem | Five things to watch for as tourney tips off | Illini took long road back to the top

It all started with hiring Antigua and Coleman, and Underwood’s decision to bring them on staff eventually led to Illinois earning a No. 1 seed in the NCAA Tournament’s Midwest Regional against Drexel Friday.

These weren’t guys from the Bob Huggins coaching tree, where Underwood’s career blossomed after spending time in JUCO hoops and low majors. Underwood went outside his comfort zone, a rare move in a profession known for loyalty and long-term relationships.

“Orlando, I’ve known him from the road,’’ said Underwood, referring to the summers spent chasing AAU. “I didn’t know Chin as well. As we continued through the process and talked to people, he became very, very impressive.’’

The most important mix was hiring two guys who worked different areas. Coleman was more of a Chicago guy, but Antigua brought something different. For a program that built winners for decades based solely on talent from the state of Illinois, hiring Antigua opened Illinois to other markets, such as New York City.

“I wanted everybody different,’’ Underwood said. “Everybody can be special in something. It was a big part of that.’’

Antigua’s connections on the East Coast landed center Cockburn, big man Giorgi Bezhanishvili and point guard Andre Curbelo. Meanwhile, Illinois also signed Dosunmu and Adam Miller with Coleman’s connections in Chicago.

Then there’s the issue of forming a bond.

“One thing I try to do is find people I like, people you enjoy being around every day,’’ Underwood said. “That’s really important. I don’t want to be around guys who get me players but I don’t like them (as people).’’

After two seasons with the Illini, Underwood probably swallowed some pride and chose to play smarter on defense a year ago. By listening to his assistants and looking at the analytics, the Illini chose not to play so far up the line on defense. It wasn’t a pack defense, but the Illini were going with a more conservative approach to stay out of foul trouble and keep opponents off the line.

It’s not likely a coincidence Illinois started winning about the time of the change.

“We keep tweaking it,’’ Underwood said last year. “We did a lot of analytics on Sweet 16 teams and teams in the conference in terms of rebounds, free throws and minutes played with the best players. The things I was concerned with were the free-throw numbers and how do we eliminate fouls to keep our guys on the floor.

“I might not want to say passive, but we’ve just backed it up a step. It helped us. It’s not anything drastic, but it’s something we felt had to be done.’’

The arrival of Cockburn and having a backstop on defense also likely played a role in Underwood’s decision. The Illini attempted to keep the big men inside rather than chasing all over the court, perhaps helping keep Cockburn and Giorgi Bezhanishvili out of foul trouble.

Not surprisingly, the numbers back up the Illini’s improvement on defense. The Illini are shooting 49.9 percent from the field this season, compared to 41.2 percent from the field by opponents. From the free-throw line, the Illini are 462 of 669, compared to 368 of 537 by opponents.

And the improvement on defense is a key variable in Illinois’ run to a Big Ten Tournament championship and a shot at winning the school’s first national title.

In the KenPom rankings, the Illini stand fifth nationally in adjusted defense. Gonzaga is No. 10, Michigan No. 7 and Alabama No. 2 and Loyola No. 1. Meanwhile, Iowa (50) and Ohio State (79) have issues on defense that must be covered up on the other end of the court.

Not yet a premium subscriber? Sign up now and get 50% off your first year of an annual subscription. Click on the promo below to get started. Enter promo code IL50.

One line of thought is that Illinois would be much more experienced with life in the NCAA bracket had it not been for COVID shutting the world down a year ago, just as March Madness was just getting into gear. So the Illini, much like a lot of teams in this field, are rookies heading into this tournament.

But there’s the flip side to that. With the pandemic also turning the NBA draft process into a murky unknown, Dosunmu made the decision to not take a risk and returned to the Illini. That also prompted Cockburn to also return. Instead of being rookies in the NBA and learning to play at the next level, Dosunmu and Cockburn are the big kids on the block, the top end of the talent level in Division I.

It’s not surprising Dosunmu was named first-team All-America by The Associated Press, the first player in school history to earn it. He was also named national player of the year by USA Today. Meanwhile, Cockburn was a second-team pick by AP.

Senior Trent Frazier, who saw his role as designated scorer change to defender and facilitator when Dosunmu arrived, let out a big scream when the team was notified of Dosunmu’s latest award.

“He’s deserved that,’’ Frazier said. “He’s the best player in the country. This is a guy who gets in three workouts a day.’’

Dosunmu’s drive – and Frazier’s reaction – are two reasons why the Illini made it back to March Madness.