Marcus Smart, without naming names, has seen the havoc that some veterans can level on rookies.

In short, not much help is offered, instead replaced by an effort to see if there’s a breaking point in the young player’s developing confidence.

Now that he’s in that position, the Celtics guard – still the longest-tenured Celts player and at this point a bona fide survivor – wants to go in another direction when dealing with his own youngsters.

“Big thing for me is giving them as much confidence as possible,” Smart said last week. “In the past, guys see rookies, and they try to break them down. That’s the wrong way to go for a rookie. Older guys aren’t taking the time to make sure that their confidence is there. It’s more like, go get your confidence on your own.

“As a rookie it’s hard to go get your confidence on your own, especially if you’re limited to certain teams, and you don’t know when you’re going to play. My job as a teammate is to give him as much confidence as I can while he’s looking for his own confidence.”

There is one name Smart proudly mentions – one of the good ones.

Smart had more self-assuredness than most when he broke into the league during the 2014-15 season. He shot and missed with impunity and asked for the biggest defensive assignments, like LeBron James.

But he was also fortunate to have Avery Bradley watching out for him.

“Avery Bradley – I knew him a little bit from growing up (in Texas) – but every time we were on the court, everything he said was a positive,” Smart said. “If I took a shot it was still positive. Everybody really took ownership to really help make sure that my confidence was there.”

After a fractious 2018-19 season, a fresh approach to leadership was needed, and Smart now wants to be that player – indeed, is that player, with the more reserved Kemba Walker the new resident star.

Smart shook his head distastefully.

“To be honest last year is out of my mind. I’m focusing on this year,” he said. “We went through that last year and it left a bad taste in my mouth. Everything from here on out is talking about this year and moving forward. This year, once we said fresh start, that’s all we’ve been talking about.”

This is where Smart’s emerging leadership style is about to take stronger hold, after the departures of last year’s failed point man, Kyrie Irving, and the lead-by-example Al Horford.

So, a vacuum had to be filled this summer. Smart, Walker, Jayson Tatum and Jaylen Brown got a head a head start on filling it with USA Basketball last summer.

“Just continue being me – bring the energy I continue to bring,” he said. “Just keep uplifting my guys, control what I can control. That’s me, myself. If I come to work every day and make sure these guys know what they need to be. Then I’ve done my job.”

This year’s rookie crop demands attention. Indeed, Grant Williams and Carsen Edwards – the latter with some 3-point fireworks during the Celtics’ exhibition-opening win over Charlotte Sunday night – will have roles with the varsity this year.

Smart, as is his wont, talks defense to his young teammates. He sees progress, beyond that jump shot, in Edwards.

“You just teach him, on the defensive end especially, talk to him in the defensive end about controlling his team, and establishing that tone because it starts with him as a point guard,” said Smart. “He definitely can defend. He’s quick – laterally quick, fast, and it helps him. He’s strong as well. He has that determination to guard.”

Smart sees himself in Edwards’ noted feistiness.

“Of course. Every time,” said Smart. “For him that’s going to be key. He has the ability to get up into guys and make them uncomfortable. He has to use that to his advantage.”

His youngsters also have off-court needs. He reached out to Tremont Waters last summer shortly after the death of the rookie guard’s father, Ed Waters.

“I had never had a conversation with him, but after those few text messages – they just reassured what the Boston culture was all about,” said Waters. “I had heard it was family first, great environment. But I hadn’t had a regular conversation with this guy, and I get a text saying if I needed anything he’s there, to have that be the first thing Marcus said was very reassuring. It hit home that where I’m going feels like home.”

They finally met in training camp.

“First time was about a week ago,” was Waters. “He walked in, we were working out. He approached me and said how’s everything. We were laughing and joking and then he brought it up. If you need anything let me know. I’ve been through it.”

In the meantime, Smart appears to be a success at positive vibes among his teammates.

“He does little things in the locker room,” said Waters. “Having everyone pick up their stuff if someone leaves something.

“During our walkthrough session he’ll pull me to the side while Coach Brad is doing everything. He’ll tell me gray means this, blue means that – he’ll go into further details about what’s going on, so that when I step on the court I’ll know what I’m doing,” he said. “He’s really smart. He knows what he’s doing, so I definitely have to listen, just continue to follow his lead to become my own person in the NBA.

“It makes it a lot smoother,” he said. “I don’t know what other teams are like, but Marcus wants to help. Makes my transition a lot easier, going from college to the NBA, where in college I knew everything the coach wanted to do, what the coach wanted on and off the floor. Now, not take a back seat, but I can learn from someone else. I have more growing to do.”

Smart is learning, too.

“I didn’t do this in my earlier years,” he said. “I tell them to go out there and do it and they catch on. But I’m spending more time with them one-on-one, groups, and talking to them whenever they have questions about things.”