DALLAS -- By now, everybody should have learned not to get too excited about a flash of brilliance from Rodrigue Beaubois.

We’ve seen a bunch of them over the past 3 1/2 years. We’ve yet to see any kind of consistency from the Mavericks’ athletically gifted combo guard.

We haven’t seen much of Roddy B. at all recently. The dude didn’t even dress for Sunday’s win in Orlando and didn’t get off the bench the two games before that.

So the fact that Beaubois was one of the only bright spots for the Mavs in Friday night’s loss to the Spurs certainly qualifies as surprising. He scored a season-high 19 points -– exceeding his total for the entire month of December -– on 6-of-8 shooting in 16 minutes off the bench.

“It was terrific,” coach Rick Carlisle said. “To me, it’s not the points. It’s the energy and the enthusiasm and the disposition.

“It’s up to him. If he plays like this, he’s got a chance to secure the backup position and he’ll challenge for the starting position. But, with him, it’s here one game and ... he’s got to establish the consistency. He showed tonight what he could do. Being able to do that night after night is hard in this league, and that’s his challenge.”

Why doesn’t Beaubois play like this more often? He was such a phenom during his rookie year -– once scoring 40 points in a win over Golden State –- that Carlisle was heavily criticized for not playing him more often.

That seems ridiculous now. Beaubois, once thought to be a major foundation piece for the Mavs’ future, has regressed each of the past few seasons to the point that nobody questions his being on the fringe of the Mavs’ rotation.

Time is running out for Beaubois -- whose rookie deal expires at the end of the season -- to make a significant impact with the Mavs.

“It shouldn’t have to be like this,” Carlisle said. “I’m a longtime supporter of his, and when he does things like he did tonight, he tells on himself. He basically says, ‘Hey, this is what I can do.’ And when he doesn’t give it to us all the time, you know, that’s where the problem is.”

Carlisle emphasized, however, that he has an open mind when it comes to Beaubois. It’s not like the Mavs have an ideal situation with 37-year-old Mike James getting almost all the backup point guard minutes fresh out of the D-League.

The playing time is there to be had. But Beaubois has to earn it.

“Obviously, I have to do a better job to be more consistent,” Beaubois said. “I have to push myself in practice, and every game I have to come with the same mindset. My teammates and my coaches are waiting for me to be more consistent, so that’s what I need to do.”

A few more notes from the Mavs’ loss:

1. Brand-new lineup: Elton Brand replaced Chris Kaman as the starter at center, although Carlisle didn’t commit to sticking with that lineup, his league-high 16th starting five of the season.

“We’ll see where it goes from here,” Carlisle said.

Carlisle clearly wanted to upgrade defensively at the beginning of games. It has been no secret that the duo of Kaman and Dirk Nowitzki has been a defensive liability, with Brand fitting in much better next to Nowitzki.

Kaman played only 12 minutes in the loss, scoring eight points on 3-of-5 shooting. Rookie Bernard James got the backup center minutes in the second half because Carlisle wanted athleticism and energy.

“Either way, coming off the bench or starting, we need his scoring,” Nowitzki said of Kaman, his former German national teammate. “We need his ability to put the ball in the basket, so he’s got to stay with it. He’s got to keep working, like everybody else when they don’t play much, and he’ll be OK. He’ll get his chances.”

2. Rest or rust: The four days off certainly didn’t do the Mavs much good. They came out sluggish and out of sync, shooting only 36.7 percent in the first half.

“For us to be able to beat good teams, you have to be ready to go right when you come out of the locker room,” said reserve swingman Vince Carter, who had 13 of his 17 points in the second half.

Making matters worse for the Mavs was the fact that they allowed the offensive inefficiency to affect their defensive intensity.

“You can’t do that, obviously,” Nowitzki said.

3. Dirk encouraged: The numbers still aren’t there for Nowitzki. But he’s beginning to feel like his old self.

“I’m encouraged, the way I felt today, especially in the first half,” said Nowitzki, who scored 15 points on 6-of-14 shooting. “I had a little more lift again in my jump shot, so at least I’m working in the right direction.”