Clarence Gaines Jr. walked into the Quest gymnasium in Chicago for the draft combine earlier this month wearing a brown/beige/orange-checkered African gown known as a dashiki.

Gaines avoided all personal contact, darting through a phalanx of scouts, general managers and media. He silently took a seat in the metal bleachers. He sat alone, as is his custom — just like his mentor, late Bulls general manager Jerry Krause, known as “The Sleuth.’’

“Bit of an odd duck,’’ one NBA scout commented, “but he has our respect.’’

Gaines, the Knicks’ vice president of player personnel and Phil Jackson’s most trusted adviser, does not treat the gym like a cocktail party, rather a place to zero in on the finest details of players.

“Clarence has a dogged nature to find out what makes a player tick,’’ Jackson wrote in an email Friday to The Post. “He says that when he watches a player, he has to be ‘moved’ to get intrigued by his talent.”

Some scouts don’t know what to make of him.

“Call him different,’’ Jazz vice president of player personnel Walter Perrin told The Post. “He has his own style — something Jerry instilled in his scouts. They sit away from people and keep to themselves. Jerry didn’t want his people talking to anybody. It gives them an opportunity to concentrate on what they’re there for.’’

Jackson made Gaines, 59, his lone front-office hire in his first month as Knicks president, originally giving him the title “adviser.’’ The former Bulls scout helped Krause build six championships teams on a small staff. Gaines worked for the Bulls for 12 years — 1988-2000 — during most of the Zen Master’s reign.

Then Gaines disappeared from the league for 14 years. He authored a basketball blog, “A Scout’s Perspective,’’ worked as a stock trader and became the most-decorated youth basketball coach with his six NBA rings.

Networking wasn’t his thing. (Gaines declined to be interviewed for this story.)

“Not being able to talk to people, you don’t get to know other people — that probably happened with Clarence,’’ Perrin said. “He wasn’t close to a lot of people.’’

Jackson knew enough of Gaines’ rabidness and work ethic as a painstaking researcher. Gaines is devoted son of the late Clarence “Big House” Gaines, the legendary Hall of Fame college coach at Winston-Salem State, where he coached Earl Monroe.

“It wasn’t his lack of social skills,’’ said Gaines’ childhood friend John X. Miller, former managing editor of the Winston-Salem Journal whose father was a big house assistant. “He didn’t want to get caught up in the noise. He observes things without the noise.’’

“Clarence still remains one of Phil’s major hole cards,’’ said Jackson biographer Roland Lazenby.

Gaines forever earned his keep in the weeks leading up to the 2015 NBA Draft — the Knicks had fallen in the lottery to No. 4, and the noise was Kristaps Porzingis was too much of a project for a 17-win club that needed instant juice.

“When he came to the Bulls from private industry, he was one of two scouts Jerry Krause had on the staff,’’ Jackson wrote in his email. “Jerry asked scouts and coaches to go to the mat for their choice of players.’’

Ex-Knick Bill Cartwright, with Gaines in Chicago as both player and Bulls assistant coach, remembers most the engaging debates between Gaines and Krause.

“He was a guy who stood up for what he believed in,’’ Cartwright recalled. “He had a really unique perspective to players and had strong confidence. He was his own person. I just remember the two of them arguing over players. All the time.’’

During the 2014-15 season’s 17-65 disaster, Gaines lobbied midseason to sign undrafted D-League guard Langston Galloway, who became the team’s best player in the final months. As the draft approached, with the stakes higher, Gaines went to bat for a rail-thin 19-year-old on a losing Spanish League team. Some scouts — even Jackson — thought it could take two years before Porzingis would make a rotation because of his body type.

But Gaines shut out the noise, saw the very rare combination of a 7-foot-3 player who can shoot from deep, pass well and had an excellent vertical. After watching him live in Spain that February, he texted Jackson that Porzingis should be considered the No. 1 pick.

“His argument for Kristaps Porzingis convinced me to make that out-of-the-box choice,’’ Jackson admitted in the email.

Despite Porzingis’ current cold war with the Knicks, he still stands as a future superstar. Gaines now zeroes in on the June 22 draft, with the Knicks holding the eighth pick and needing backcourt and wing help.

“He’s got a unique perspective of players and their character and how they’d blend into a team,’’ Cartwright said. “He’s been around a basketball team his whole life. It’s not necessarily he knows players for the triangle but an understanding how they could fit into a team and bring the team value. That’s the biggest part of scouting.’’

Monroe, a Knicks legend, remembered Gaines in the 1960s as a young tyke — a fixture at Winston Salem’s practices run by his famous dad.

“Big House was very disciplined and made us do lots of running,’’ Monroe said. “We took it out on Clarence, ran by him and plucked him on the head. Give him credit. He never told his dad.’’

Miller, his boyhood friend, and Gaines served as waterboys for the Winston-Salem basketball and football teams.

“Clarence was always around his dad — in team situations,’’ Miller said. “The aura of his dad is always shining on him. He still posts old photos on Facebook of his former players. His father’s passion was photography. Big House recruited only leaders and followers with the right aptitude — not physical but mental aptitude. Clarence learned you need players who can lead, players who can follow.’’

Working then for the Baltimore Bullets, Krause, who idolized Gaines, drafted Monroe. Eventually, Krause hired Gaines’ son in Chicago and groomed him. Gaines’ scouting reports are legendary — including one in 1996 on unheralded draft prospect Derek Fisher he later posted on his blog. Gaines nailed everything about the future Knicks coach.

“Krause had such an eye for talent, a sense for gifted people,’’ Lazenby said. “Clarence gained plenty by working for Krause. Lots of people can watch a game but they don’t see, don’t study and don’t have the insane work ethic it takes to do all the research like Clarence.”

Gaines’ offbeat nature comes in handy during pre-draft player interviews. At the combine in Chicago, Jackson gave Gaines kudos for his role in the interview room.

“It’s always interesting to meet these young men and have an opportunity to get to know them,’’ Jackson said. “They have pretty much a set story they’ve been taught. But we hope to knock them off base a little bit and see what their personalities are. Usually we’re pretty good. I have a master interviewer in Clarence. He even has his dashiki on.’’

According to Miller, Gaines, though not given credit, was most instrumental in the Bulls drafting Scottie Pippen.

Other than Gaines, Jackson made no front-office hires in his three-year-plus reign and retained all the scouts.

“Phil has a small circle of friends,’’ Perrin said. “He has a sense of loyalty to him, someone he’s felt comfortable working with in the past.’’

Whether he has on his “dashiki’’ or not, Gaines will be fighting in the war room next month, fighting for the next Pippen. People close to Jackson say he always is listening.