It’s become obvious that the Dallas Mavericks might not advance far this season unless they can find a way to keep Samuel Dalembert out of foul trouble. That became evident Friday night against the Indiana Pacers. When Dalembert had just one foul, the Mavs led the much taller Pacers at halftime 41-39. But once he went to the bench with four fouls with 7:55 remaining in the third quarter — the Mavs were leading by six at the time — the Mavs went into a disappearing act with backup center DeJuan Blair on the court. From the 8:33 mark of the third quarter to the 5:33 mark of the fourth, the Mavs went from being ahead 51-43 to being behind 89-68. Dalembert re-entered the game with 8:57 left to play, but by then the Pacers were leading 80-66. Since the 98-77 exhibition loss at Indiana, coach Rick Carlisle has had two conversations with Dalembert about his foul issues. “We talked about it after the game and we talked about it today,” Carlisle said after Saturday’s practice at American Airlines Center. “The challenge is he’s got to be aggressive and yet he’s got to be vigilant about not taking bad fouls.” Forward Dirk Nowitzki believes one or two of Dalembert’s fouls can be avoided because they normally come via moving screens. “As a defender you’re going to pick a foul up here and there with being active,” Nowitzki said. “With the shot-blocking you’ll pick up some fouls. “But we’ve got to make sure that he doesn’t get those one or two moving screens a game. Those really hurt.” Any time Dalembert gets into foul trouble it’ll hurt the Mavs, because their regular backup center, Brandan Wright, is out indefinitely with a small, non-displaced left shoulder fracture. In the meantime, the 6-foot-6 Blair and Bernard James are serving as Dalembert’s backup.