The Celtics’ $6.1 billion sale to a group led by Bill Chisholm is one step away from completion.

A source confirmed to the Herald on Thursday that the sale commitments have been finalized and Chisholm’s new ownership group is set.

The Boston Globe was the first to report the latest development, citing a letter sent to existing team shareholders.

The only box left to check for the franchise is approval by the NBA’s Board of Governors, which is expected to vote on the sale in June or July.

Chisholm’s full list of minority partners has not been disclosed, nor has the exact value of his majority interest, but it includes Robert Hale, a current member of the Celtics’ board of directors; Bruce A. Beal, Jr., the president of Related Companies; and private equity firm Sixth Street Partners.

Per NBA rules that limit private equity investment in teams, Sixth Street cannot hold more than a 20% stake in a franchise, and its share cannot be larger than that of the controlling owner, Chisholm.

Wyc Grousbeck, the face of Celtics ownership since Boston Basketball Partners LLC purchased the team for $360 million in 2002, plans to remain in his roles as team CEO and governor through the 2027-28 season before handing over control to Chisholm.

Both are Massachusetts natives who grew up rooting for the Celtics, with Chisholm spending his formative years in Georgetown on the North Shore before attending Dartmouth College. He is in the process of relocating from California, where he co-founded Bay Area-based Symphony Technology Group, to the Boston area.

“Bill is a terrific person and a true Celtics fan, born and raised here in the Boston area,” Grousbeck said in the initial sale announcement on March 21. “His love for the team and the city of Boston, along with his chemistry with the rest of the Celtics leadership, make him a natural choice to be the next Governor and controlling owner of the team. I know he appreciates the importance of the Celtics and burns with a passion to win on the court while being totally committed to the community. Quite simply, he wants to be a great owner. He has asked me to run the team as CEO and Governor for the first three years, and stay on as his partner, and I am glad to do so.”

Chisholm and Grousbeck have watched several Celtics games together from courtside seats since the impending sale was announced. This week, Chisholm attended Game 4 of Boston’s second-round playoff series at Madison Square Garden and Game 5 at TD Garden, wearing a black Jayson Tatum jersey at the latter after the Celtics star underwent season-ending Achilles surgery.

The Celtics will look to avoid elimination Friday night when they visit the New York Knicks in Game 6.

The Luke Kornet game

Two minutes into the second half of Wednesday night’s must-win game, things looked dire for the Celtics’ frontcourt.

Al Horford had just picked up his fourth foul with 20 minutes still to play. Kristaps Porzingis had tried to play through his persistent illness but couldn’t do so effectively, posting a minus-12 with one point and one rebound over 12 brutal first-half minutes.

Porzingis “couldn’t breathe” at halftime, according to head coach Joe Mazzulla, so it was decided he would not reenter the game unless Boston “absolutely needed him.”

How did the Celtics solve this personnel problem? With a whole lot of Luke Kornet.

Boston’s third-string center played nearly the entire second half and delivered the most important performance of his winding NBA career. He scored 10 points, grabbed nine rebounds and blocked a career-high seven shots to help lift the Celtics to a 127-102 win in Game 5 of the Eastern Conference semifinals.

“He was great, both ends of the floor,” Mazzulla said. “… He made some big-time plays for us.”

Five of Kornet’s blocks came during a six-minute stretch in the third quarter, during which Boston broke what had been a tight game — the teams were tied 59-59 at halftime — wide open. He played the entire third quarter, sat the first 2:18 of the fourth, then reentered after Horford was called for his fifth foul. Mazzulla rolled with Kornet the rest of the way, keeping him on the floor until Boston pulled its regulars with 2:34 remaining.

“He came in and just seemed to always be in the right position,” Derrick White said. “Seven blocks is crazy. He was unbelievable tonight and really stepped up when we needed him. He’s had a great season and was big time for us tonight.”

With Tatum’s ruptured Achilles leaving a permanent hole in Boston’s starting lineup, Mazzulla could look to plug in Kornet for Game 6 on Friday. A loss in Game 6 or a potential Game 7 back in Boston next Monday would end the Celtics’ season.

“Whatever Coach asks me to do, I’m just there to do it,” said Kornet, who began his NBA career with the Knicks in 2017. “Whether I’m starting or coming off the bench, not playing at all, that kind of comes with the responsibility that that is, and you have to do your best job with whatever position that you’re put in. And that’s what we’re always trying to do as a team.”

White fills scoring void

Luka Doncic, Victor Wembanyama, Derrick White.

Those are the only NBA players ever to record a stat line like the one White posted in Game 5.

With Tatum unavailable, White carried the scoring load for the Celtics, racking up 34 points on 9-of-16 shooting. He went 7-for-13 from 3-point range and, in an unusually aggressive showing by his standards, 9-for-11 from the foul line in the win. He also blocked three shots on the defensive end.

The veteran guard became the first player ever to notch at least 34 points, three blocks, seven made threes and 11 free-throw attempts in an NBA playoff game. Only Doncic (in December 2023) and Wembanyama (in December 2024) have reached those marks in any contest, with the latter requiring overtime.

“It’s not like someone can step and do what JT does at the level he does it,” he said. “So we kind of have to play a little differently and just find ways to create offense, to rebound, just everything he does on the court. Everybody’s got to step up. We did that tonight, and we’ve got to try to find a way to win Game 6.”

The Celtics needed White’s scoring, plus similarly impressive performances from Brown and Kornet, to overcome the loss of Tatum, who is not expected to return until sometime in 2026.

“Obviously, it’s tough to see,” said White, a close friend of Tatum’s. “I texted him. And that was kind of all I could do, really, was to text him. Just tell him that we believe in him and he’s going to have a great comeback from this setback. There’s really not much I can do, especially at this moment, but I’m going to support him throughout his whole journey, and I know he’s going to do whatever he needs to do to get back out there with us.”

Tatum also sent a pregame message to his teammates, which Kornet described as him “encouraging us to go out and keep doing the job, keep trying to accomplish the goal.” The Celtics will look to continue that journey Friday night at MSG.

“Our back’s against the wall,” White said. “It’s win or go home at this moment, and none of us want to go home. We understand that it’s only going to be tougher. We haven’t won anything yet. We’ve got to find a way to go to New York and win again.”