Celtics president of basketball operations Brad Stevens and majority owner Bill Chisholm addressed reporters for nearly 45 minutes Monday afternoon, offering their explanation for one of the most consequential trades in recent franchise history.

The top headline from their joint news conference was the word Stevens used — 12 times in all — to justify sending Jaylen Brown to the Philadelphia 76ers for Paul George and four draft picks: “Optionality.”

Here are four other takeaways:

— Chisholm, taking part in just his second press conference as Celtics owner and first since last September, mostly listened as reporters lobbed question after question at Stevens.

But he made clear after one of the few direct questions he did receive that he and his ownership group did not instruct the front office to trade Brown.

“Absolutely not,” Chisholm said. “This was all about basically trying to win, and I think really trusting in our process. I think we have the best front office in the NBA. They put in their work, and they came to the conclusion this was the best way for us to win. The mandate is to win, and I just have to keep saying that. We’ll spend whatever it takes to do that. The mandate is to win. This was Brad and his team came with a recommendation: ‘This is the way we’re going to win.’

“And I looked at it, and I had the same reaction. I was like, ‘Wow, this is — the fan in me — it’s really tough.’ And then recognizing — I said this back in the fall — I recognize that I have accountability, and I’m accountable for it. Brad’s accountable to me for it, and his team’s accountable to him, but the mandate here is to win. And we came to the conclusion, they convinced me this was the best way for us to win. And I got there. I did.

“But it was hard. It was really hard. And I recognize this is a big move. And frankly, I didn’t anticipate it would happen this fast in our ownership.”

Each of the first two offseasons under Chisholm’s new ownership regime has been defined by seismic roster change. Last year, the Celtics lost four members of their 2024 championship team (Kristaps Porzingis and Jrue Holiday to trades; Al Horford and Luke Kornet in free agency) in moves aimed at pushing the team below the second apron of the luxury tax.

Chisholm, a Massachusetts native and lifelong Celtics fan who made his fortune in private equity, said those moves, and the decision to trade Brown, were “basketball decisions,” not cost-cutting measures.

“I just don’t necessarily agree with the premise there that they were salary-based,” he said. “Every decision that was made, prior decisions, those were basketball decisions. We would have gutted the team for our future had we not done these things. The second apron is a real thing. I know you know that. But those were basketball decisions. I put this one in the same category, as well.

“The money (between Brown’s salary and George’s) is a marginal difference. So it’s not about the money at all. This was trying to put together the right set of players and assets to win now, and then next year, the following year, and the year after that. That’s what this was about. None of these were about money.”

Stevens, Chisholm said, has “the green light” to spend in pursuit of winning.

“I know there’s people who feel like there must be a smoking gun somewhere, but that’s just not what this is about,” he said. “I say it, I’ll keep saying it, but I’ll also prove it to you. The times we have the opportunity, we’re going to do that. We’ve given ourselves the flexibility to do that. It’s fine to keep asking the question, because I know we have to prove it, and we will.”

The Celtics were set to pay Brown $57.1 million this season, $61 million next season and $65 million in 2028-27. He also would have been eligible for a two-year contract extension this summer.

— Brown said in a Twitch stream last week that he felt disrespected by the Celtics’ handling of the trade, believing he deserved more transparency than the franchise afforded him.

“I will say we had several talks. If he feels that way, then I’m sorry about that,” Stevens said. “I am, genuinely. Because he’s a meaningful person in all of our lives and certainly mine. Like I said, we had a lot of open discussions about here or elsewhere. And even, I would say he and at least his agent were well aware of even teams that had the most cursory interest. So at least that was well communicated, or at least communicated. And so we tried to do that to the best of our abilities.

“As things get further down the line, it’s complicated to ultimately get it over the finish line, with any deal. But I’m sorry that he feels that way.”

Brown was the subject of rampant trade rumors in recent weeks, with those intensifying after the Celtics’ attempt to flip him for Giannis Antetokounmpo failed. When the market for his services was more tepid than expected, he faced criticism from pundits and anonymous sources over his advanced metrics, contract value and personality.

“You do your best you can at being upfront before that could possibly happen,” Stevens said. “… If I didn’t do a great job with it, I think we’ll probably both have different versions of that, of what those conversations looked like, but I do think that’s what I would regret, not necessarily for any other reason (than) I just, you know, I like Jaylen.”

— Stevens said he did not solicit Jayson Tatum’s input before trading his longtime co-star.

“I have a real hard, fast rule that I don’t ask other guys about other guys, because it’s not – I don’t want to put them in that position,” he said. “And so he had none.”

What was Tatum’s reaction to the move?

“I think Jayson and Jaylen – I mean, Jayson is a friend of Jaylen, right?” Stevens said. “And so, we have not talked in great depth about that. I think that, again, I didn’t keep him in the loop. I didn’t talk to him the next day. I didn’t want to put that on him or anyone else that’s in the playing group. I know how little I sleep (I got). Nobody else needs to feel that.

“And I think ultimately, when you put in the work and the sweat with somebody for nine years, there’s obviously going to be a great appreciation for that person.”

— Stevens dropped one schedule-related nugget: The Celtics and 76ers will play each other twice this preseason and four times during the regular season. It’s not yet clear when Brown will visit TD Garden for the first time as a visitor.

“The Philly part, I’m with you,” Stevens said. “That is a hard thing to trade a guy that you, first of all, care so much about, and secondly, you have so much respect and admiration for, to a team that just beat you in the playoffs and that you’re going to literally play six times before the playoffs next year with our two preseason games. But I do think that ultimately, when you do a deal, you have to be thinking about you first and the optionality it creates for you.

“If I was being honest, if that exact deal came from a team out West and you were comparing the two, then you’d probably take the team out West. But that’s not the way it would work.”