Celtics have an emerging leader in Jae Crowder

Jae Crowder provides a toughness and intensity that the Celtics had lacked since the departure of Kevin Garnett. Jim Davis/Globe staff/File 2015

NEW YORK — When the Celtics finally parted ways with Rajon Rondo after years of rumors, Jae Crowder was considered a throw-in, the most unfamiliar name in the four-player deal between Boston and the Dallas Mavericks.

Crowder is now an integral piece of the Celtics’ future, a former second-round pick whose chances of lasting in the NBA were considered minuscule just three years ago.

His rise has been swift, from a long shot to make the Mavericks roster to a rotation player to an emerging star in Boston. He signed a five-year, $35 million contract this offseason, making him another trade steal for president of basketball operations Danny Ainge.

Crowder’s evolution has progressed so quickly that he has become a voice of reason and a legitimate leader in a locker room that contains a plethora of youngsters. The Celtics are a team of evenly talented upstarts, and the king of the upstarts is a small forward who dons dreads.

“It raises everything,” Crowder said of his added responsibility. “Your level of intensity, your level to attention to detail, being accountable each and every day. Everything raises and it’s a part of it and I feel like I’ve been leading by example more than verbally. That’s my role on the team, to lead by example.”

It seemed the Celtics and coach Brad Stevens warmed to Crowder’s style and toughness from the moment he arrived last December. The team lacked a tough guy, an intimidating factor since the trade of Kevin Garnett to the Brooklyn Nets in June 2013. Crowder was self-made, a product of two junior colleges and Marquette who was considered undersized, a fullback-sized small forward.

He plays with a passion, a fury that younger and more lauded players lack.

“I’m still going to help the young guys out, still help to pick us up when we need it,” he said. “At the same time, I think David Lee does a great job being verbal and Isaiah [Thomas] does a good job being verbal. I pick and choose my spots. I just lead by example.”

Crowder averaged 9.5 points in 57 games with the Celtics last season, and his strong defense against LeBron James in the first round of the Eastern Conference playoffs cemented his status as a cornerstone. His ascension in training camp is a point of pride for Stevens.

“I think Jae’s been really good,” Stevens said. “He’s aggressive. He’s been an everyday guy. Nothing matters as far as the circumstances surrounding it, he plays hard. He plays really hard and he gives everything he’s got. If he makes a mistake, he usually corrects it and he’s the kind of guy you like to have on your team.”

What’s different about this season than the previous three for Crowder are the expectations. Whether the Celtics improve on their 40 wins last season and emerge as a contender in the East will partially depend on Crowder’s success and improvement.

He will need to become more of a dependable scorer and better perimeter shooter. But he doesn’t appear concerned about the pressure.

“This is my sanctuary, this is where I’m comfortable,” he said. “I don’t look into anything but playing basketball and try to improve as a player, a team player and build from each year. I look back at [my career] and I’m [surprised at my success] but the work that I put in, it don’t surprise me where I’m at today. I put the work in when no one else is around. That’s what it’s all about.”

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Rookie R.J. Hunter scored 11 points in Wednesday’s 109-105 exhibition win over the Brooklyn Nets, and also had 4 rebounds, 4 assists, and 4 steals in 29 minutes. Considered a 3-pointer shooter and scorer when drafted out of Georgia State, Hunter is showing more playmaking ability than expected.

“I think it’s pretty obvious just watching him that he has a feel,” Stevens said. “It just comes pretty natural, little passes, simple plays, being able to put the ball on the money to other people, understanding where his opportunities are going to come. He’s got a good feel for the game and as he continues to make those shots and feels more comfortable, he’s going to be better. Defensively, he’s way ahead of where I thought he would be.”