“Joe Mazzulla’s tough love sparks growth for Celtics’ Neemias Queta.”

For Mazzulla, it was more complex than simply throwing a player out for lack of hustle. It was a teachable moment. The first step in turning Queta into a difference-making player, perhaps the Celtics' center of the future, is to make him realize he's capable of it.

“He’s just grown a lot as a player, but he also doesn’t know how good he can be,” Mazzulla said. “He has a great ceiling so the standards are very high and I think he did some great things for us tonight.”

“But when you're as good as he can be, we all have to keep him at that level every night. It is therefore a credit to him that we were able to coach him.

“It’s a credit to (his teammates) for supporting him. But you can see what he's capable of when he gives his best, so he can be a real asset to us. He works really hard. He cares. He wants to be trained. He’s starting to realize how good he can be and he’s working on it.”

Queta was a second-round pick by Sacramento in 2021 out of Utah State and spent two years in the Kings' system, primarily in the G-League. Sacramento waived him in September 2023 to make room to sign aging center JaVale McGee, and the Celtics signed the big man to a two-way contract five days later.

He worked his way up the Celtics' rankings, racked up minutes last season and then had his contract converted to a regular NBA contract, making him eligible for the playoffs.

This season, his role has expanded, particularly with the absence of Kristaps Porzingis, so much so that Mazzulla decided to give Queta his first NBA start on Monday. He finished the game with 10 points, 7 rebounds, 1 steal and 1 block in 23 minutes – and also learned an important lesson about staying committed.

Queta is a relaxed guy, a soft-spoken speaker, but he can't lack passion on the floor. He has to play with a certain power and viciousness.

“He was just trying to hold me accountable,” Queta said. “In the first few games I felt like I was always a step behind. I don't know. You listen to what they have to say and try to do it better on the next piece.

“Maybe it was because I was nervous at the first start. You never really know, but I just tried to sort it out by getting used to being in that position.”

The Celtics are hoping Queta develops long-term as he is a cheap center option who won't command significant money until the next two years. The Celtics are in the second tier of the salary cap because they rewarded their core with long-term contracts. They urgently need to promote cheaper talent from within their own ranks.

Queta is one of her projects. It is unclear why other clubs did not sign Queta when he was out of work for a few days, as he has fascinating physicality and skills. At 7 feet tall and weighing 245 pounds, he can fly over the rim for alley-ups and rebounds and has shot-blocking skills.

“All of these guys are unselfish and constantly trying to make the right play,” he said. “When I'm under the rim, I feel like they understand that they just have to throw it up there and most of the time I'll go get it.”

His disadvantages so far are defensive positioning and foul issues, but these can be fixed. The Celtics thought they had a key cornerstone in Robert Williams, but he couldn't stay healthy and never developed an offensive game.

Queta appears ready to learn how to be an NBA starter, and the Celtics believe he can be an important contributor. Mazzulla will be harsh on mistakes, but good things seem to happen every time Queta is on the floor. He scored a plus-31 in his 23 minutes on Monday.

And a productive Queta means less of a burden on 38-year-old Al Horford. While other NBA clubs are desperate for productive bigs, the Celtics have an abundance of them, including an up-and-coming rim protector who is currently reaching his potential.

“I feel like I still have a lot to learn or get better at,” Queta said. “I’m learning new systems, new ways to protect myself, and being effective in different ways. The more I can develop and refine these skills, the more impactful I can be.”

Gary Washburn is a Globe columnist. He can be reached at [email protected]. Follow him @GwashburnGlobe.