Nowitzki knew that was about to change, pointing to this week's four-day trip with stops in Oklahoma City, Memphis and San Antonio as a potential measuring stick for the Mavs.
No grand conclusions should be drawn from a couple of November games, but the Mavs are well aware they have a lot of work to do if they're going to establish themselves as a legitimate threat to do playoff damage in the West. They didn't need losses to the Kevin Durant-less Thunder and the Zach Randolph-less Grizzlies to know that. But the point has been hammered home so far on this trip, particularly during Tuesday's 110-96 loss in Memphis.
"We've got to get better," Nowitzki said. "We knew that during the six-game win streak. We've got to keep working. We've got to get better defensively, work together, end the possession with rebounding and then we can get our flow game working. We gave up  in OKC and 110 to a slow-paced team. It's just not good enough."
All things considered, the Mavs are still in pretty good shape as they head to San Antonio to wrap up the trip Wednesday night. Their 9-6 record has them tied with Oklahoma City for third in the West, which is especially encouraging considering all the medical issues the Mavs face.
It would have been reasonable to project a slow start for the Mavs considering their two highest-paid players, Wesley Matthews and Chandler Parsons, are coming off major surgeries and have had their minutes limited. Point guard Deron Williams missed all but one preseason game because of injuries. With so many new pieces, the Mavs could even have difficulty fostering team chemistry.
But those are also reasons to believe the Mavs can improve as the season progresses. Parsons has pushed his minutes up to 25 per night -- but probably will still sit on the second night of a back-to-back against the Spurs -- and is a few weeks away from being a full-time player again. Matthews has no more restrictions and has shown signs of finding his offensive rhythm in a new system and surroundings. Center JaVale McGee, who was cleared to play over the weekend, can add a different dimension with his size and athleticism after he settles in and returns to playing shape.
But these last two losses have left a bitter taste in the Mavs' mouths. The fact they've committed 36 turnovers in the two losses really bothers them.
"I feel like we're beating ourselves right now," said guard Raymond Felton, who scored 14 of his team-high 16 points in the fourth quarter as the Mavs attempted to make a comeback after falling behind by as many as 25 points.
"We need to clean this up," center Zaza Pachulia said. "This is something that can be changed in one day. This is not something that you need weeks and months to work on. We have done it. We just have to use our smarts and our experience not to make those mistakes. I don't know if it's lack of energy, I don't know if it's lack of concentration, but whatever it is, we need to clean it up."
The turnovers were a point of emphasis going into the Grizzlies game. It was harped on during Monday's practice and film session, and Tuesday's meeting and shootaround. It was written on the whiteboard in the Mavs' locker room with a big asterisk by it.
It's a problem that is uncharacteristic for a veteran-loaded Mavs team that prides itself on possessing great basketball intelligence. The Mavs had committed the second-fewest turnovers in the NBA before this trip.
"What made us and makes us a good team is our ability to take care of the ball and our ability to get shots," Matthews said. "If you take away one of our biggest strengths, which is getting shots, because we're turning it over, well, then it's like not handing the ball off to [Adrian Peterson]."
Of course, the caliber of competition probably has something to do with Dallas' sudden problems.
"This is one of the better defensive teams in the league," coach Rick Carlisle said of the Grizzlies. "Tomorrow we're playing the best defensive team in the league, by percentage and by numbers. We have to do better, and we will."