DALLAS – His second NBA season is three days away from getting underway, and Dallas Mavericks point guard Dennis Smith Jr. is already talking like a team leader.

So much so that coach Rick Carlisle paraphrased a line from the old EF Hutton commercial when describing Smith.

“When he talks people listen,” Carlisle said following Sunday’s practice at the Lympo practice facilities. “He’s not a guy that’s going to give you a lot of unnecessary constant chatter.

“But he understands when to step forward and be strong as a leader verbally.”

Smith is so locked into what he’s doing that as the Mavs open the regular season Wednesday at 9:30 p.m. in Phoenix, he’s only concentrating on one thing.

“I just want to make the playoffs,” Smith said. “That’s it. When I say make the playoffs, I mean doing whatever I can to be the best me, and everything else will fall in line and the accolades that I’m aiming for will fall in line and we’ll make the playoffs.”

And how exactly will the Mavs make the playoffs in the rugged Western Conference?

“Be really good defensively, get good shots, play within the game plan,” Smith said. “If we do that every night I think that’ll give us a good shot.”

The Mavs’ good shot at advancing to the playoffs may very well hinge on the play of Smith, who buried himself in the gym in the offseason in an all-out attempt to become one of the NBA’s best playmakers. If there was a gym available – no matter what city he was in this past summer – Smith was there working on his game.

“I’ve seen a lot of growth, really in all areas,” Carlisle said of Smith. “Maybe the most important area is as a team leader.

“We’re really trying to keep things as simple as possible for all of our guys. And with that said, the point guard is always going to have the most complex job of ball distribution and mixing in an aggressive attack to score, to set up play-making opportunities, and there is real nuance for all that stuff. But he’s smart, he wants it and I really love the way he’s playing. He gets a little better every day.”

Smith most notably wants to improve his defense this season, so he wound up studying some of the game’s best defenders – including Mavs players DeAndre Jordan, Dorian Finney-Smith and Wesley Matthews. Smith said, minus some minor lapses, he saw some major improvements in his defense during the Mavs’ four preseason games.

“I watch film after every game defensively, so I’ll be able to make that improvement,” Smith said. “I see Wes and DJ how they stay engaged on the defensive end, and (Finney-Smith).

“I’ve been watching a lot of really good defensive guys this summer. Even now I still watch a lot of other really good defensive players in the league and watch how they guard certain things, so I’ve been doing my homework.”

Smith, who just shot 39.5 percent from the field and 31.3 percent form 3-point range last season, also did his homework in regards to learning how to improve his shooting stroke. That’s where he’s been leaning on Peter Patton, the Mavs’ new shooting coach.

“I’m just trusting my mechanics,” Smith said, who averaged 15.2 points and 5.2 assists last season. “We’ve got Peter in now. He told me my mechanics weren’t bad.

“It’s that I got to trust and stick with my follow-through and things of that nature. The simple things that you first learn. The same things that my pops tell me. It’s been working so far, so I’m going to stick with it.”

With the Mavs also having rookie Luka Doncic an accomplished ball handler, Smith knows there will be times this season when he’ll be asked to play off the ball. He addressed that notion, too, over the summer.

“I’ve gotten better at it,” Smith said. “I played a lot of off the ball in pickup (games), but to be honest I really don’t feel like I’m having the ball too much less than I did last year.

“I think it’ll probably be easier to stay engage if I just talk. On the ball I’ve been doing a lot better job. It’s just off the ball I’ve got to make improvements, and I think it’s just talking.”

The Mavs lost their season opener last year to the Atlanta Hawks, 117-111, in a game Smith scored 16 points and dispensed 10 assists. He wouldn’t mind having similar results in this season’s opener – with the Mavs winning, of course.

“It was my first NBA game last year, so I was super juiced up,” Smith said. “I played off complete adrenalin last year.

“We lost a close game. I don’t want to repeat the end results, so we plan on getting a win Wednesday.”

NOTES: Coach Rick Carlisle has ruled forward Harrison Barnes out of Wednesday’s regular season opener against the Phoenix Suns. Barnes sat out all four of the Mavs’ four preseason games with a strained right hamstring. “He is gradually increasing his workouts,” Carlisle said. “We’re going to shoot for a full live practice by the end of the week, so that’s where we are.”. .Dwight Powell sat out Friday’s game against the Charlotte Hornets with a sore right knee, but participated in Sunday’s practice session. . .Forward Maxi Kleber was back at practice Sunday after missing the second half of the game against the Hornets with tightness in his lower back. “It locked up and I had pain, so I couldn’t move really well,” Kleber said after Sunday’s practice. “It’s fine now. I had it once before, so I know it’s like two or three days and then it’s gone, so I’ll be fine.’’. .The Mavs trimmed their roster down to the NBA maximum of 17 on Sunday by waiving guard/forward Ding Yanyuhang. The 17 players include the two players with two-way contracts – Kostas Antetokounmpo and Daryl Macon. . .In summing up Sunday’s practice, Carlisle said: “We had an aggressive practice today. It was good. With two practices to go, we’ll get into a few other detail things the next couple of days and taper it back a little bit.”. .Carlisle said the one way his defense gets better is just by playing. “We’ve got to just continue to take small steps to get better,” Carlisle said. “It’s a hard game to guard these days. Everybody is so spread out. Just about everybody shoots threes, so it’s always a task.”. . Dennis Smith Jr. and rookie Luka Doncic played the first four preseasons as if they had been playing together for five or six years. So how did these two youngsters get on the same page so quick? “Just through honest communication,” Smith said. “We’ve got to be honest with one another and we’ve got to be able to criticize one another, and also build the other person up. And at the same time we’ve got to be receptive to that on both ends.”. .Doncic, who is 19 years old, starting playing pro ball in Europe at age 16. It wasn’t the NBA, but it was pro basketball against grown men. Smith said: “When you see him play you can tell that he has been playing pro for a while.”