DALLAS — There's nothing worse than watching a team full of millionaires consistently play with indifference.

That's what the Mavericks do way too often.

They did Monday in a pathetic loss to Oklahoma City, which didn't have its two best players — Kevin Durant and Jeff Green.

Ridiculous.

We shouldn't be surprised, though.

The Mavs do this all of the time, even though you'll probably get a quality effort against San Antonio tonight because they're embarrassed by their performance against the Thunder.

Or they're scared because Mark Cuban is peeved. He ripped the Mavs for their effort against Oklahoma City and threatened to remove any players from the roster who don't want to make hustling a way of life.

Good for him.

It's about time, because they've been doing it all season.

The Mavs already have lost six games by at least 20 points, and there's still more than a month left in the season.

No good team does that.

Just so you know, the Mavs lost only seven games by at least 20 points in the last three seasons combined. Last season, it happened just once.

Here's a bet: The Mavs will lose their seventh game of this season by 20 points on Thursday at New Orleans because it's the second game of a back-to-back.

So the Mavs will have every possible excuse to lay it down. Trust me, they don't need much incentive.

Think about it. How many times have you heard Rick Carlisle or Dirk Nowitzki or Jason Kidd or Jason Terry question the Mavs' effort after yet another blowout loss? Too many to count.

See, this team lacks mental toughness, in part, because its leaders are doing a poor job. Dirk and Kidd, that's on you.

Terry has only been back for two games after breaking a finger on his left hand, but he must also set a better example.

Your leaders should set the tone. They're supposed to show the other guys how to play the right way. Dirk, the only player on this team good enough to impose his will on a game, needs to demand more from his teammates.

It doesn't matter whether he does it publicly or privately. He just needs to do it.

Maybe this mentally soft team thinks just because Houston's Tracy McGrady will miss the rest of the season and Phoenix's Amare Stoudemire is probably out for the year, they won't have any problems making the playoffs.

Well, that's simply not the case.

The Rockets are actually better without McGrady because he can't dominate the ball, and they feed Yao the way you're supposed to feed a big man. Since Phoenix fired Terry Porter a few weeks ago, the Suns have been at their run-and-gun best, and Shaq is playing his best basketball since leaving the Lakers.

These Mavs can't just walk onto the court and sleepwalk past mentally whipped opponents.

No one fears the Mavs these days. Why should they?

Good teams know that if they smack the Mavs in the first quarter, they'll lay down for the rest of the night. Bad teams know that if they fight early, they'll build a huge lead before the Mavs realize they need to fight back.

Sometimes, the Mavs rally to win, as they did Friday night against Oklahoma City, when they erased a 12-point deficit in the last four minutes and won in overtime.

Other times they don't.

It's embarrassing.

Carlisle is not without blame.

He must figure out a way to help the Mavs on days they're not shooting well.

Carlisle believes the Mavs win if they play good defense and rebound. But this is a team built around Nowitzki, Kidd and Terry, and the Mavs don't play passionate defense unless they're on an offensive roll.

In the past two seasons, Dallas has one victory when scoring fewer than 90 points.

They're 0-8 this year.

The coach is different. Not much has changed.