MIAMI — Derrick White sported a different haircut, shot nearly four percentage points worse from three and didn’t initially want to leave when he found out the San Antonio Spurs traded him to the Boston Celtics in 2022.

“I saw that this morning. Three years is crazy. It’s been a good three years,” White said.

“Pop called me and came to my room … I was pretty upset when I got traded, but looking back, it was probably the best thing to happen to me and thankful for where I’m at.”

White later smiled remembering that he and Popovich initially went to the wrong rooms.

Now, White is a Celtics champion, received a long-term extension with the Celtics and has become a fan favorite who put in one of the great baskets in team history on the floor he stood on reminiscing about his time with the team on Monday. White’s game-winner in Game 6 of the 2023 Eastern Conference Finals forced a Game 7 that nearly allowed Boston to achieve the first 0-3 comeback in NBA history. That loss, and the changes that followed, set in motion White becoming an indispensable Celtics starter.

Offseason alterations to the roster and Marcus Smart and Malcolm Brogdon leaving elevated White above the role that often left him off the floor at the end of games. Now, it’s difficult to imagine him not starting and playing all the key moments for a team that relies heavily on his playmaking.

“I just expected him to do what he’s doing now,” Joe Mazzulla said on Monday. “He’s always been a great player. To me, it was more about having him see that and having him be able to do that alongside … other really good players, which can be a little bit challenging, at times, coming into this environment. So he’s just gotten better, naturally. He’s one of the smartest players I’ve coached with his ability to think in real time, situationally, what needs to be done.”

“Defensively, that was the first thing we watched was our defensive teach tape and where he was gonna make an impact, how we were gonna use his versatility and then offensively, just growing as a pick-and-roll ball handler, and being able to play against different coverages. Then, he’s a big time shot-maker. So he’s been great.”

His famous put-back, unbelievably, marked his only crunch time shot attempt of the 2023 playoffs.

The deal wasn’t universally beloved at first. CelticsBlog infamously panned it. Boston entered the deadline 31-25, buoyed by a six-game win streak following the team’s maddening .500 start. The cost — Josh Richardson, Romeo Langford, that year’s first-rounder and a pick swap — proved difficult even for Brad Stevens. He accepted, but noted in his press conference after that the distant future swap is what keeps you up at night as an executive.

It marked Stevens’ first big bet on the team with his previous significant trade of Kemba Walker for Al Horford worked amazingly, but was originally conceived as a salary dump. White struggled at first, later acknowledging a difficult acclimation to the Celtics despite his former assistants Ime Udoka and Will Hardy leading the staff at the time.

He finished the season shooting 40.9% from the field and 30.6% from three with the Celtics, then fell to 36.4% FG (31.3% 3PT) in the playoffs. Shooting improvement became mandatory after the Finals loss to the Warriors exposed his offense with a 1-for-10 finish from the field.

“(My game’s) a lot different, obviously,” White said. “Just trying to get better each and every year, and just add little things to my game to try to make me a better player. The organization has done a lot to help me improve and just try to continue to get better with it. (I’ve improved at) shooting, the obvious answer, and then I think I’ve just grown as a person and player as well … I had moments in San Antonio where I was up-and-down, so I just think more consistency is what I was focusing on, and obviously now, I’m shooting a lot more threes than I probably thought I would ever shoot.”

White vaulted from 31.2% between the Spurs and Celtics in 2022 to 38.1% in his first full season when Mazzulla assumed the head coaching role and Ben Sullivan took over as his shooting coach. He praised his head coach again on Monday, stressing the belief Mazzulla showed in him as crucial to his breakout. That summer, after the conference finals loss, White and his long-time trainer Marcus Mason added more muscle to his frame and reduced the lean on his shooting motion to stabilize his three-point efficiency.

He exploded with a 39.6% season from deep while adding 2.0 more attempts per game, flirted with All-Star status in each of the next two seasons and devastated opponents with 40.4% shooting into the 2024 championship run, all while becoming a perennial All-Defensive Team name. In many ways, White became the Celtics third star, and they’ve missed him when he sits more than any other teammate. Boston is 5-5 without White over the past two seasons outside of their two wins to close last season over resting Charlotte and Washington teams.

There’s some magic to his game, too — the Miami put-back rolling into his hands, his prayer trapped above the break in Saturday’s Knicks game at the end of the clock resulting in three run-stopping free throws and his errant in-bounds on Monday bouncing back to him for a late clock heave three that fell into the net.

Nobody questions the trade anymore after moments like those, and with ring in hand, there’s a chance White becomes a Celtic for life. That he adds levity with trick shot competitions, his baseball glove always nearby and constant banter with Tatum only helps. After Monday’s win, he and Tatum debated the greatest Celtics and Lakers of all time.

“Derrick’s just a tremendous player,” Payton Pritchard said. “Doesn’t really have a weakness. Very good person and fun person to be around. As far as the locker room goes, he helps in that aspect. You can plug him in anywhere, he can play with anybody, he was a very great pickup and obviously Brad did a great job with that trade.”