Brad Stevens holds his first press conference after the Celtics were eliminated from the playoffs by the Heat at the Auerbach Center on Thursday in Boston. Stuart Cahill/Boston Herald

BOSTON  — For anyone expecting sweeping changes from the Boston Celtics this offseason, team president of basketball operations Brad Stevens is throwing a bit of cold water on that idea.

After a season in which the Celtics fell one game short of a return to the NBA Finals, Stevens said he sees a team in need of small tweaks, not massive disruption to the leadership or its young core.

“There was a lot that went right, and we can’t lose sight of that,” Stevens said Thursday during his season-ending news conference. “It’s not far. … It’s really hard to get in the mix. So, we just have to figure out how to be a little better.”

That will start at the top with Coach Joe Mazzulla, who Stevens said will return after guiding the Celtics to 57 wins and the No. 2 seed in the Eastern Conference.

Asked directly if Mazzulla is the right person to lead the team going forward, Stevens was unequivocal.

“Yeah, I think he is,” Stevens said. “I thought he did a really good job with this group. Everybody’s going to overreact to the best players and coaches after every game. That’s always how it is. We know that going in, so we have to be able to judge things on the whole.”

That the team was able to finish the regular season second in both offense and defense and fight back from a 3-0 deficit in the conference finals is evidence of Mazzulla’s leadership, Stevens said.

Given the rapid-fire introduction Mazzulla received after being named interim coach just days before training camp, Stevens said he now measures Mazzulla’s head-coaching experience in dog years.

“He’ll only get better at anything that he can learn from this year, because he’s constantly trying to learn. And he’s accountable,” Stevens said. “When you can show all those things through the expectations and the microscope that he was under, that’s hard to do.”

Stevens said the Celtics do plan to add at least one assistant coach with extensive NBA experience on the bench this summer, filling the spot vacated when Damon Stoudamire left to become Georgia Tech’s coach in March.

As far as changes to the roster, Stevens said while they will always monitor the league landscape for potential additions that could help, he likes his team’s existing core.

Due to NBA rules that restrict what executives are allowed to say about players with pending contracts, Stevens declined to speak specifically on the decisions needed to be made this offseason involving Jaylen Brown (eligible to sign a five-year supermax extension on July 1) and restricted free agent Grant Williams.

“I’ve had nothing but great conversations with Jaylen,” Stevens said. “I can say, without a doubt, we want Jaylen to be here. He’s a big part of us. We believe in him and I’m thankful for him. … I’m really thankful that when those guys have success they come back to work. And when they get beat, they own it and they come back to work. And so I know that’s what they’re about. And that’s hard to find.”

Stevens said his plans will start with doing as little as possible to disrupt the infrastructure of what he believes is a team that can win a championship.

“At the end of the day, we love our foundation. We love our core. And that’s really our focus and our priority,” Stevens said.

Stevens said Tatum had “a pretty decent” ankle sprain in Game 7 but is feeling “a little better.” Malcolm Brogdon, who dealt with a strained right forearm during the conference finals, has yet to decide whether to have surgery. Stevens said Derrick White’s knee injury in Game 7 was just a hyperextension and sprain.

ERIC LEWIS was not selected as one of the 12 referees who will work the NBA Finals between the Denver Nuggets and Miami Heat, while the league continues to look into whether he used a Twitter account to defend himself and other officials from online critiques.

Lewis had been chosen to work the finals in each of the last four seasons. This year’s finals referees were announced by the league Thursday morning, about 12 hours before the start of the title series.

After some now-deleted tweets were revealed by a pair of Twitter users last week, the league opened an investigation into whether Lewis violated NBA rules by speaking about officiating in an unauthorized manner. It has not been determined if Lewis was using the account, which utilizes the name “blair cuttliff.” The account was deactivated briefly last week but was active again Wednesday evening.

76ERS: Philadelphia named 55-year-old Nick Nurse, whom the Toronto Raptors fired in April, as its new head coach. Nurse led the Raptors to the 2019 NBA championship after they beat Joel Embiid and the Sixers in Game 7 of the Eastern Conference semifinals.

Nurse replaces Doc Rivers, who was fired after he led the 76ers to their second straight 50-win season behind Embiid, this season’s league MVP, but again failed to lead them to the Eastern Conference finals.