They have no one capable of stopping Russell Westbrook.
No one player can do it.
The Mavs must use a detailed team effort, the kind they certainly discussed during Sunday's video session to keep Westbrook from dominating Game 2 of this Western Conference quarterfinal.
If Westbrook is going to consistently make mid-range jumpers, control the game's tempo and play lockdown defense on Terry, then the Mavs have no chance to win this series.
Westbrook was the best player in Game 1 with 28 points, 5 assists and 4 rebounds. Yes, he had five turnovers, but most of those were the results of Kidd's thievery as opposed to bad decisions.
Westbrook, usually the definition of a volume scorer, made 13 of 23 shots. And this wasn't one of those games where his speed and athleticism allowed him to attack the bucket at will.
He took only five shots in the lane, making two -- and those didn't occur until the fourth quarter.
That's a problem for the Mavs.
Durant scored 25 points, but needed 27 shots to do it. Marion takes away Durant's space and makes him earn every basket, including the contested 15-foot game-winner he made in Game 1.
Westbrook, by definition, is a rhythm shooter as opposed to a player such as Jet, who's a catch-and-shoot player.
Westbrook likes to use the dribble to find his shooting rhythm. The Mavs let Westbrook find a comfort zone in the first quarter, when he made four of six shots and scored nine consecutive points during one stretch.
The Mavs were so determined to keep him from getting into the lane that they gave him too much room to maneuver.
"I like the way we did a lot of things," Mavs coach Rick Carlisle said. "He made shots. We have to make it tougher for him to get looks. We have to do a better job of taking him out of his rhythm."
The Mavs' problem is they didn't expect Westbrook to play so well.
They figured they'd get the player who struggled in April, making only 38.9 percent of his shots while scoring 20.8 points per game. Or they might get the petulant hothead with a propensity for meltdowns that they saw in the Western Conference finals last season.
Remember, the only game the Thunder won in the conference finals occurred when Westbrook spent the fourth quarter on the bench.
This is a different player.
He has more confidence after another sensational season, and he has the mental stability and security that accompany a long-term contract. He signed an extension in January.
All he has to do is worry about basketball.
We've all heard and read the stories about his desire to be "the man" instead of Durant's sidekick.
Who knows if they're true. There was no evidence he was slightest bit unhappy with his role in Game 1.
In the third quarter, Westbrook worked his way into the lane. As the defense attacked him, he delivered a perfect wrap-around pass behind Brendan Haywood's back to Serge Ibaka for a two-handed dunk.
Later, during a two-on-none fastbreak, Westbrook stopped at the free throw line and fed Durant for an uncontested dunk.
Then, there was his phenomenal fourth-quarter defense on Jet, who scored 20 points while making eight of nine shots in the first three quarters.
Jet missed his only shot of the fourth quarter.
Westbrook denied him the ball with the same intensity he usually attacks the basket. He even denied him out to half court.
As good as Jet is -- he spent the first three quarters in the zone -- he's not good enough to score without the ball. Carlisle blamed himself for not being creative enough to get Jet the ball.
At one level, we shouldn't be surprised at Westbrook's effectiveness because he's bigger, faster, quicker and stronger than Jet.
It's just that he usually expends so much energy on offense that playing defense isn't at the top of his priority list.
But these are the playoffs and priorities change. Controlling Westbrook is now the Mavs' top priority.
If they can't do it, then their championship reign will end within the next 13 days.