Steve Pagliuca says the NBA is going “back to the future” where the salary cap is concerned.

This summer’s salary cap adjustment, which lowered the number to $99.093 million for the 2017-18 season, and set the luxury tax level at $119.266 million, took an especially draconian hit on the Celtics.

That tightened cap number is the reason Avery Bradley was introduced as a member of the Detroit Pistons last Thursday, thus giving the Celtics room to account for Gordon Hayward’s four-year, $128 million contract.

But with Isaiah Thomas demanding the arrival of his Brinks truck next summer, and Marcus Smart’s first big payday also at hand, the Celtics’ cap challenges have only begun.

So after the feel-good spirit of 2016, when an influx of new television money had teams like the Celtics spending freely, teams are going back to a previous sensibility.

“There was a time when teams had lots of cap space with the increase in revenues,” Celtics managing partner Pagliuca said last week in Las Vegas. “Now we’re entering a period where cap management becomes imperative.

“Now we’re going back to the future, where people had to work hard for cap space.”

Thus the extended process of finally signing Hayward 10 days after reaching agreement with the All-Star forward. Danny Ainge and his assistant general manager and cap guru, Michael Zarren, indeed worked hard to pull together all the moving parts.

But the Celtics are likely on the brink of a true throwback, to the days when Celtics ownership happily paid luxury taxes throughout the era of Paul Pierce, Kevin Garnett and Ray Allen.

Pagliuca isn’t sure the team will re-enter tax-land next summer, but if exceeding the tax line means once again having an annual chance of reaching the NBA Finals, then the co-owner says so be it.

“I don’t know if it’s inevitable, but if we feel it’s going to help us win a championship, then we will,” he said. “We have a history of doing what we need to do to win.

“But you have to be careful — if you sign people to bad contracts, it’s going to preclude you from signing other players. But I’m very happy with how it’s gone.”

Ownership and management is basically on notice by Thomas, who has been bluntly open about his expectation for a maximum contract, after years of playing at a bargain price, including $6.3 million in 2017-18.

Ainge and his staff have been entrusted with determining Thomas’ market value beyond that, and much will hinge on whether the Celtics point guard is able to duplicate his spectacular 2016-17 season.

Whether both sides agree to a maximum contract — it would be the Celtics’ third behind Hayward and Al Horford — remains to be seen. Beginning at a $1.50 tax for each dollar a team is over the tax threshold, and an ascending rate with each increase of $5 million, the tax is even worse for repeat offenders. Then the rates increase by a dollar.

But Pagliuica admittedly likes what Ainge & Co. have done to this point.

“I think they’ve come up with a really good mix of veterans and young talent,” Pagliuca said. “We have a powerful combination.”

If that projection holds, then Ainge knows that ownership will open the bank account, and maybe even the Brinks truck.

“So many things can happen between now and next year that could change things,” Ainge said. “But our ownership has been very willing to pay taxes in the past, and that’s because it’s their objective to win.”

Brown spreads the coaching gospel

Larry Brown, at the invitation of Memphis coach David Fizdale, was part of the Grizzlies delegation last week in the role of an advisor.

Not surprisingly, the 76-year-old Hall of Famer wants to rejoin in the NBA in this kind of capacity. No one has spent more time shuttling between the NBA and college basketball — Brown is the only coach in history to win championships in the NBA (Detroit, 2004) and NCAA (Kansas, 1988) — and in the case of Brown, what’s one more move?

“I would love to do what a Pete Carril has done, or a Johnny Bach or a Tex Winter,” he said, naming some of the most famous assistants and gurus in league history. “My only thing is to share what I know.”

Doc Rivers once offered Brown a place on his Celtics staff, and Brown, whose coaching tree has endless reach, laughs when he thinks about Rivers now. Rivers actually played for Brown in his previous incarnation with the Clippers — as a player over the second half of the 1992-93 season.

But for now Brown is traveling the country as a special coaching guest star, after leaving Southern Methodist University in 2016 after the school was put on NCAA probation.

“I went around the country, spent time working with (coaches), and learned,” he said. “This year Fizdale asked me to come with him — he’s family. He worked for Mike Woodson (in Atlanta), who worked for me (in Philadelphia and Detroit).”

Brown, who grew up in Brooklyn, is old enough to have been a Brooklyn Dodgers fan, and that long-gone era is never far from his thoughts.

Consider his reaction to seeing his former SMU player, Celtics rookie Semi Ojeleye, wearing No. 37.

“I’m pretty sure Ed Roebuck wore 37 for the Dodgers,” said Brown, who was correct.

Roebuck played for the Dodgers their last three seasons in Brooklyn, from 1955-1957.