If they don't win Game 4, then they're fooling themselves to think they can recover from a 3-1 deficit against an opponent that has outplayed them for the bulk of the series. So this becomes an all-or-nothing night for Dallas. Win by establishing a style that can overcome the Heat's hard-closing defense, and the Mavs can instantly convert this into a best-of-three with hope of prevailing. Lose, and they can forget about it.
The talking point at the Mavs' practice Monday was to provide offensive help for Dirk Nowitzki. He scored 34 points in the Mavs' narrow Game 3 loss and is averaging 28.4 for the Finals while shooting 45.9 percent. The other Mavs -- apart from Shawn Marion (19-of-38 from the field) -- haven't been nearly so sharp.
"I have to get more opportunities at the basket to be effective," said sixth man Jason Terry, who is averaging 14.3 points while converting 13-of-34 (38.2 percent). "That's on me, being aggressive, looking for more opportunities."
The Mavs were already short-handed without small forward Caron Butler -- imagine the difference he might have made. In his absence they need explosive scoring from Terry, but twice Terry has gone scoreless in the fourth quarter.
"I take it to heart," Terry said. "The success of this team is predicated in the fourth quarter, myself and Dirk being opportunistic with the basketball. He's had a lot of opportunities and gotten it done. Two out of three games, I have not. He needs some help. I'll be there to lend him a hand the rest of the way."
As they've done throughout the playoffs, the Heat have been closing fast on Terry and the other outside shooters. They've rarely felt comfortable taking shots that would be uncontested against most team defenses, though in Game 3 they appeared to be faking more often and stepping inside to make plays.
"We have to find a way to get Jet some freedom and get him off some movement, and he's got to make some shots for us," Nowitzki said of Terry. "He's a big reason why we're here, because he's one of the great fourth-quarter players we have in this league. But they've been able to really take that away. So if we can get him going and get him off some movement and free him and get him shots, and get our shooters some better looks, so when the fourth quarter comes they're going to step in there with confidence and be ready to play a little more defensively ...''
You get the idea. The Mavs have a lot of improvements to make. And yet, they've been in every game.
At the other end, Dwyane Wade has been terrific while emerging as the early favorite for Finals MVP. He's averaging 29 points, 8.7 rebounds and five assists and shooting 56.7 percent.
"Obviously, I struggled in the Chicago series," Wade said of the Eastern Conference finals. "This is a different series for me and for my team. I'm playing in a good rhythm, good flow. I've been in attack mode a little differently.
"Besides [Eddie] House and Udonis [Haslem], I'm one of the three who has been able to win a championship. I've been able to understand there's a moment -- not saying our players don't understand big games. I've been here before. I've experienced a very weird, tough series [in 2006 against the Mavs] to win the championship. I don't want none of these guys for us to walk away and say if we would have did this or would have did that. If you get beat, you get beat because you put it all out there and did everything you said you wanted to do."
That LeBron James has been relatively quiet as a scorer is both irrelevant to the bigger picture as well as ominous. James came to Miami to create plays that would help win championships, and in helping to create for Wade he has helped bring Miami within two wins of the title. At the same time, he is available to score when needed in Game 4.
Don't expect Miami to ease back now that it has regained home-court advantage.
"We continue to approach every game like we're the more desperate team, like we need to win," Haslem said. "When we play with a desperate sense of urgency, that's when we're at our best."
That's the same kind of formula the Mavs are seeking.