DALLAS – If DeMar DeRozan is ultimately going to quiet his hometown critics and earn the $40 million he’ll be paid over the next four seasons, he’ll need to learn to become more ruthless on the floor and more demanding of his teammates when they need pushing the most.

The roster-depleted Dallas Mavericks were everything that DeRozan and his sluggish teammates, playing the second game of a back-to-back and fourth game in five nights, were not in the first quarter of the Raptors’ eventual 109-104 defeat. They led exactly once, 2-0, on DeRozan’s opening jumper. Toronto trailed by as many as 16 and by double digits nearly throughout until a late, futile comeback attempt.

By the end of the first quarter, Dallas — playing without Dirk Nowitzki, Shawn Marion, Elton Brand and Roddy Beaubois — led 36-24, shooting 60 percent, and kept the Raptors at arm’s length the rest of the way. It was Toronto’s fourth loss in five games, hardly the start preferred by a franchise seeking a resurgence under second-year coach Dwane Casey.

No, it didn’t help that a sprained ankle sustained the night before in the blowout loss at Oklahoma City sidelined streaking point guard and leading scorer Kyle Lowry. But, don’t talk to the Mavericks about injuries. This game was determined by hustle and one of Mavs coach Rick Carlisle‘s favorite words — disposition. Just peek at the halftime rebounding totals to see which team brought it: Dallas, near the bottom of the league in every rebounding category, 31, Toronto 13.

On a night made for DeRozan to pull up his teammates from the opening tip, to will his tired club to compete on the road, it just wasn’t there. At the half, DeRozan had 10 points on 2-for-5 shooting while being guarded mostly by Mavs rookie forward Jae Crowder.

“I thought they did a good job,” Casey said of the Mavs’ defense. “We didn’t have a heavy dose of going to him in the first half as much as we did the second half. We tried to get the ball moving from side to side a little bit more in the first half and I thought he got it going in the second half. I don’t know if it was Crowder or just DeMar.”

DeRozan finished with 24 points, getting to the free-throw line 10 times, with seven assists and six rebounds. He missed all three of his 3-point attempts.

Just 23 years old and in his fourth NBA season, DeRozan beat the Halloween deadline and happily signed a four-year, $40 million extension with the franchise that drafted him ninth overall in 2009 after one season at USC.

“It’s definitely big because this is where I want to be at the end of the day,” DeRozan said. “I’ve been here through the tough times and I definitely want to be here when things turn around so that’s my big picture, how I look at it. And for them to keep me here, it’s definitely a blessing.”

The franchise, general manager Byran Colangelo and Casey could have waited until after this season, but they rolled the dice on an extension, believing DeRozan is on the cusp of transforming his off-the-charts athleticism into the total package.

“He’s a core of our youth movement,” Casey said. “We’re banking on him, we’re betting on him and I see nothing but good things. He’s made strides this year from last year so we’re banking on him continuing to make those strides going into the future.”

The belief is that Lowry will make DeRozan better and there’s already early proof of that. Other pieces such as Landry Fields, who has disappointed, rookie center Jonas Valanciunas, Andrea Bargnani and Amir Johnson can be blocks around their young wing.

“They’re coming along well,” DeRozan said of the pieces around him. “We had a tough couple games, close games … but but we’re learning. I think it can’t do nothing but help us; in the long run I think we’re going to be just fine.”

But in the short-term, if the Raptors continue to struggle, DeRozan and his new extension will get the scrutiny.