While Tatum has consistently posted better statistics in recent years, Brown’s more assertive style and vocal leadership have prompted debates on television, radio and social media about whether he is Boston’s true leader and top talent. Kidd jumped headfirst into the conversation at Saturday’s practice ahead of Sunday’s Game 2, casting a contrarian vote for Brown at the expense of Tatum, who had 16 points (on 6-for-16 shooting), 11 rebounds and five assists during a relatively quiet Game 1.

“Well, Jaylen is their best player,” Kidd said. “Defensively, he picked up Luka [Doncic] full-court. He got to the free throw line. He did everything, and that’s what your best player does. He plays both sides, defense and offense, at a high rate, and he’s been doing that the whole playoffs.”

Kidd’s statement, which caught a room full of reporters off guard, deflected attention from the Mavericks’ Game 1 struggles and became the chief topic of conversation during Boston’s media availability. The Celtics’ chemistry was a major asset on both ends during Game 1, and Tatum painted Kidd’s praise of Brown as an attempt to disrupt their togetherness.

“We wouldn’t be here if we didn’t have [Brown] on our team, and we can say that for a lot of guys,” Tatum said. “We have all played a part in getting to where we’re at, and we understand that people try to drive a wedge between us. I guess it’s a smart thing to do or try to do. We’ve been in this position for many years of guys trying to divide us and say that one of us should be traded or one is better than the other. It’s not our first time at the rodeo.”

Tatum and Brown, who both were No. 3 draft picks, have faced questions throughout their seven seasons together about whether they are an ideal pairing. Their shortcomings in past postseasons, including the 2022 Finals against the Golden State Warriors and the 2023 Eastern Conference finals against the Miami Heat, also have prompted trade rumors and speculation about a possible breakup.

This year, Boston has been less reliant upon Tatum after adding Jrue Holiday and Kristaps Porzingis in offseason trades. Tatum’s scoring, field goal attempts and usage rate dropped in 2023-24 as he ceded opportunities to Boston’s newcomers. Nevertheless, the Celtics won more games, registered a higher point differential and posted a better offensive efficiency rating than at any point during Tatum’s career.

During this playoff run, Tatum has scored 25.3 points per game — his lowest postseason average since his second season in 2018-19 — and is shooting just 29.9 percent on three-pointers, the worst mark of his postseason career. Yet Boston is 13-2 in the playoffs and sits three wins away from its first championship since 2008.

“We’ve been extremely focused on what our roles and our jobs are,” said Brown, who is averaging 24.8 points, 6.1 rebounds and 2.6 assists during the playoffs. “We have all had to sacrifice. Jayson has had to do that at the highest of levels, and I respect him and tip my cap for it. Right now, at this point, it’s whatever it takes to win, and we can’t let any outside interpretations try to get in between us.”

Boston cruised past Dallas in Game 1 despite a subpar scoring game from Tatum, who didn’t attempt a shot in the first eight minutes, committed six turnovers and faced significantly more defensive attention than Brown. During his postgame comments, Tatum said he had been “nervous in like an anxious way, like a little kid,” to get back to the Finals after Boston fell short in 2023.

With Porzingis back from a calf injury and an offensive system that consistently generates open three-pointers for a lineup filled with quality perimeter shooters, the favored Celtics don’t need Tatum to match Doncic shot for shot to win this series. Tatum, to his credit, has mostly avoided his worst habits — ball-stopping and settling for tough contested two-pointers — while hitting the glass and playing high-energy defense.

Dallas won Game 2 in its three previous series, including bounce-back victories after Game 1 losses to the Los Angeles Clippers and Oklahoma City Thunder. But the Mavericks will need more than Kidd’s mind games to even the Finals: Their ball movement bogged down badly in Game 1, leaving Doncic as the only reliable source of offense.

Kyrie Irving must be more composed than he was Thursday, when he scored 12 points on 19 shots, and Kidd said Doncic must do a better job of reading Boston’s defense, which is designed to limit Dallas’s corner three-point attempts and lob passes at the rim.

“Boston is going to give the layup to Luka, so he’s got to take it,” Kidd said. “They’re not going to give him the lob, and they are not going to give the corner three. So it’s two-on-two [in the paint], and we have to take advantage of that.”

As Doncic tries to find ways to unlock Boston’s defense, all eyes will be on how Tatum responds to Kidd’s tactics. The Celtics blew a 2-1 series lead in the 2022 Finals and fell into a 3-0 deficit before losing the 2023 East finals, earning a reputation for mental fragility and ineffective late-game play.

After going an impressive 21-12 in games that were within five points in the last five minutes during the regular season, Boston is 4-0 in such games during the playoffs. And when the Mavericks appeared poised to erase the Celtics’ 29-point lead in Game 1, Brown keyed a 14-0 run late in the third quarter that squashed any possibility of a collapse.

To fully bury their ghosts from years past, the Celtics must continue to prove they are older, wiser and more resistant to meltdown.

“As long as we focus on the truth, the things that we talk about every day and the relationships that we build with each other, they can look at it however they want,” Celtics Coach Joe Mazzulla said in response to Kidd’s comments. “What goes on in our locker room, how we communicate with each other, how we build relationships with each other and how we treat each other on and off the floor, that’s the most important thing.”