The Celtics are heading back to the NBA Finals with the belief they can win it all this time

INDIANAPOLIS — There were no champagne bottles in sight for this eyewitness account. The gray folding table centering Boston’s visitors locker room inside Gainbridge Fieldhouse was covered with cans of beer and puddles of hazy IPA. The Celtics are waiting to uncork those bubbly bottles after next round, should they capture the real crown, an 18th banner in franchise history after Boston swept Indiana with a 105-102 victory in Game 4 on Monday night.

“We understand what we need to do and lock in and do whatever it takes to get four more wins,” said Derrick White, after the Celtics’ do-everything guard splashed the game-winning triple with 45 seconds to spare.

That didn’t stop staffers and players from posing with the Eastern Conference finals trophy, named after Celtics great Bob Cousy. They belted Drake lyrics oozing from a massive JBL speaker. Sam Hauser, Boston’s reserve marksman, used a pair of scissors to crack a hole in the bottom of one beer, and joined an equipment manager to shotgun the can. And then another. Kristaps Porziņģis, who has been out with a calf injury since the first round, calmly poured a Corona into a white paper cup. Luke Kornet, who sprained his left wrist in Game 2, grabbed a Kona Big Wave before walking out the door.

Even with that missing 14-feet of frontcourt firepower, Boston handled two crunchtime contests at Indiana with exemplary execution when every small element matters most. These players and personnel certainly believe this is an evolved team from the one that reached the Finals stage two years ago, that claimed a 2-1 series edge over Golden State before the Warriors flipped the script and Stephen Curry clinched his fourth ring. Porziņģis is expected to be ready for Boston’s likely matchup with Dallas more than a week away on June 6. Jrue Holiday has proven to be worth every piece of the significant package Boston traded to Portland for his veteran services.

Yet the difference, Boston seems to believe, is not just who’s wearing the Celtics’ classic green. “I think we’ve just applied everything that we’ve learned,” said Jayson Tatum.

“Time has gone by,” said Jaylen Brown. “Experience has been gained. And I think we are ready to put our best foot forward.”

After trailing by as much as 18 midway through the third quarter of Game 3, Boston closed the game with a 13-2 run and a monstrous two-way, team effort. On Monday, the Celtics limited Indiana to just 19 points in the fourth quarter, and the Pacers went scoreless in the final 3:33 of Game 4. Derrick White credited Boston’s steadiness through these crucial possessions to the painstaking habits that head coach Joe Mazzulla ingrained within every training session at Red Auerbach Center.

“It starts in practice,” White said, “the ‘championship stations’ that Joe loves to do.”

Mazzulla sets up different exercises at each basket around the parquet floor just off the Mass Pike. Sometimes, they focus on details as mundane as inbounding the ball. Other times a box-out drill right out of high school two-a-days. “Just trying to pick little things that we see on a nightly basis that can impact winning and effect losing,” Mazzulla said. “And we just practice ‘em over and over and over again until they become second nature.”

“It’s the little things that we talk about that can help you win a championship,” said Tatum.

Maybe that’s part of what Brad Stevens, now Boston’s president of basketball operations, saw in Mazzulla when Stevens named the 35-year-old as this decorated franchise’s interim head coach just before the 2022-23 season began, after Ime Udoka was suspended, sending Boston’s follow-up campaign to that last Finals appearance into unchartered waters.

When Stevens was just 36 and jumped to the Celtics’ sideline from Butler, he won over players with scrupulous attention to detail, drilling them on specific end-game situations and placing each guy in all five positions of each action, so they were always prepared for every angle and every possibility. When Boston returned for its first practice after claiming the No. 1 seed in the Eastern Conference this regular season, Mazzulla ran his roster through what he called “training camp for the playoffs,” a morning Al Horford called harder than anything the Celtics endured during the preseason, with coach barking the players through challenges like playing full-court for three minutes without dribbling.

They have another eight days of time to prepare for this next phase, departing the arena around midnight for their charter back to Boston. Brown’s bags weigh a bit heavier, thanks to his Eastern Conference finals MVP trophy — named after Celtics great Larry Bird.

“I think I’m one of the best wings, guards in this game. I thought this year I’ve taken a level, and I’ve increased it. I took the matchup, I picked up guys full court, I chased guys off screens, I battled with bigs and I feel like I should have been All-Defense,” Brown said.

His swooping block on Andrew Nembhard with 1:05 to play was only outdone by his driving dish on the next possession, drawing a crowd in the paint, before the All-Star zipped the game-winning assist to White in the right corner.

“I like to set my hat on just being a versatile two-way wing and can do both at any point in time,” Brown said, “and the last four minutes of this game, you saw that.”

He scored 10 in the final frame, finishing with a team-high 29 points. Tatum added another 26 points, 13 rebounds and eight assists, earning four of the other nine media votes for the MVP honors. These two stars have grown from boys to men and from prospects to playoff performers stride for stride. Now, more than ever, they seem primed to finally cross this finish line together.