NEW YORK — Dan Burke began compiling notes on the nuances of the 76ers’ offense about a week ago, when fellow assistant Sam Cassell’s entrance into health and safety protocols reminded him that, during this pandemic surge, any staffer could be separated from their team at any time.

Still, when he and Doc Rivers took their routine COVID-19 test before their Thursday-morning meeting and Rivers’ result came back positive, Burke was convinced it must be a mistake.

“I started feeling like I skipped two months of school, [and] I better get ready for the finals,” Burke said.

By 9:30 p.m., Burke’s Sixers pullover had turned from light gray to dark, drenched in water uncorked by his team in celebration of an impressive 110-102 victory over the Eastern Conference-leading Brooklyn Nets. It was the NBA lifer’s first win as a head coach, the role Burke will hold for however long Rivers remains in isolation.

» READ MORE: Joel Embiid, Tyrese Maxey shine as Sixers top Eastern Conference-leading Nets

Burke constantly emphasized that his duty is to be an extension of Rivers, that he must “do right by the job, right by Doc, and right by the players.” But those who have worked closely with Burke during his three-decade career know he is more than ready to shoulder such responsibility on short notice.

“This is one of the really great success stories in the history of our league,” said Pacers coach Rick Carlisle, who has known Burke since they were both on the Portland Trail Blazers’ staff in the mid-1990s. " … The thing that was always so consistent about Dan was he was always completely prepared.

“The players always had just a total trust in him and that he had done the work and that he had put them in the best possible position to succeed. That will carry forward as he takes over for Doc for however long this goes.”

This is not an entirely unfamiliar situation for Burke, who before Thursday had twice filled in when then-Pacers coach Nate McMillan had to miss a game for personal reasons. Unprompted, Burke self-deprecatingly pointed out that he went 0-2 in those matchups — against Golden State in March of 2019 and at Charlotte the season prior.

Now, Burke can expect to be the Sixers’ acting head coach for at least six days, after the NBA shortened the isolation period for asymptomatic positive COVID cases if testing determines the person is no longer infectious to others.

A defensive guru

When asked to describe Burke during a phone conversation with The Inquirer minutes before Thursday’s tip-off, Carlisle used the phrase “understatedly dynamic.”

Carlisle first met Burke when Burke was the Trail Blazers’ head video coordinator, and immediately respected his knowledge of the game, tireless work ethic and ability to relate to players. They both went from Portland to Indiana in 1997, when Larry Bird was hired as the Pacers’ head coach. Burke eventually worked his way up, first to opponent prep coach and eventually to the front of the bench as an assistant over a 23-season span.

Along the way, he developed into a defensive guru. Tactically, Carlisle described Burke as a coach who “has been on both the adaptive and inventive sides” of that end of the floor. He highlighted the schemes Burke helped create and implement when Frank Vogel was the Pacers’ head coach that “have really stood the test of time,” including emphasizing verticality when protecting the rim and aggressively guarding the ball to force turnovers and push opponents into tough shots.

That immense defensive knowledge also makes Burke an underrated offensive coach, Carlisle said. And when it comes to teaching and communicating with players, Burke’s style is a blend of old-school and laid-back.

“He’s just truly authentic as a person,” Carlisle said. “I think players really appreciate that he is himself, that he’s always going to tell them the truth, but he’s always going to do what’s respectful and on-point and relevant to whatever the specific situation is.”

That made Burke an ideal fit as Rivers assembled his first Sixers coaching staff ahead of the 2020-21 season.

Rivers has long designated a “defensive coordinator,” a philosophy acquired while visiting with NFL coaches, including Bill Belichick. Rivers and Burke were also both influenced by the late Dick Harter, the former Penn coach who was an assistant during Rivers’ playing stint with the New York Knicks in the early 1990s and who was on staff with Burke in Portland and Indiana.

Last season, the Sixers ranked second in the NBA in defensive efficiency (107 points allowed per 100 possessions) while Joel Embiid, Ben Simmons, and Matisse Thybulle earned NBA All-Defensive honors. Burke stressed his scheme has no “gimmicks” and relies on containing the ball, “shrinking” the court, and being disciplined in fulfilling the individual assignments the unit needs.

“When you have a coach who really believes in what they’re saying and they trust their knowledge of the game, no matter what, it has a way of rubbing off on the players,” said Thybulle, a rangy wing who constantly balances using his exceptional athleticism and instincts to make impact plays while staying within the confines of Burke’s system.

“I’ve never felt constricted on defense, and I always feel like I’m able to go and make the plays that I can to help the team.”

A win to remember

Despite Burke’s wealth of experience, he acknowledged stepping in as head coach comes with a variety of new responsibilities.

Because he is typically so focused on the defensive end of the floor, he has not worried much about the spots Embiid and Seth Curry like the ball or what actions to run against a specific defensive matchup. He does not often speak to the media, and joked, “How long are you going to keep me here?” when he noticed two full water bottles on the table for his pregame availability.

Burke put Rivers on speakerphone for Thursday’s meeting to reiterate the game plan against the Nets. Fellow assistant Jamie Young would assist with his rotations throughout the game. He wanted every staff member to be empowered to speak up during the game, but insisted, “Let’s not be chaotic. Let’s be orderly. Let’s be disciplined in what we want to do and quick and timely and concise in the timeouts.”

When asked if past influences and experiences will subconsciously influence his in-game coaching, Burke said, “We’ll find out.”

“I don’t want to make it anything about what I would do different or anything like that,” Burke said. “But if I see something, I’ll have to go with my gut. Something I remembered from the past, maybe just a tweak in spacing.”

During Thursday’s first timeout, Burke sat in front of the Sixers’ huddle and put marker to white board. He had a lively discussion with an official in front of the bench while Kevin Durant shot free throws during the third quarter. With less than two minutes to play, he threw his arms up in disgust when James Harden drew a foul on Tyrese Maxey. He clapped vigorously when Embiid converted the game-clinching free throws with 15.3 seconds remaining. He received congratulatory postgame high-fives and handshakes from staffers, before the players provided the locker-room shower.

» READ MORE: Best and Worst: Joel Embiid's newest milestone, Matisse Thybulle's solid D

“Everybody was a part of it,” Burke said. “I guess it’s no exaggeration [to say] it was a great team win, and I needed their help.”

Added backup center Andre Drummond: “He gave us everything we needed to be great tonight and successful.”

How many more times Burke will roam the Sixers’ sideline is unclear. The team only has three games between now and Jan. 12: a home matchup with Houston on Jan. 3, a Jan. 5 trip to Orlando, and a Jan. 7 home date with San Antonio.

Carlisle said he hopes this stretch becomes an opportunity for Burke to show he should be a head-coaching candidate. Yet when asked about Thursday’s personal milestone, Burke immediately pivoted the focus back to his team. He used his hand to demonstrate that the players are much stronger when they come together to form a closed fist, rather than operating as spread-out fingers.

There’s a reason why Burke could immediately call back to his two losses as an NBA head coach, however. “Those stick in your mind,” he bristled before Thursday’s game.

Burke’s drenched pullover suggests his first victory will, too.

“I don’t know if they expected me to do an Irish jig or something,” he said. “They’re all staring at me, but it’s fun. … I don’t know if we ever say it enough: [When you have] a lot of great character and big hearts, you got a chance every night.”