While the Dallas Mavericks flourished on offense through the early part of the 2019-20 NBA season, their defense has been atrocious.

Per ESPN's Mike Peasley on Twitter, longtime Mavs head coach Rick Carlisle has emphasized defense in recent team practices, spending most of instruction working with the captive-audience players to improve on that end of the floor.

Dallas is 11th-worst in opponent points per game, giving up 112.2 a night. Additionally, the 4-2 Mavs have a 108.7 defensive rating—again, 11th-worst in the NBA—and can't compete in the long term with other teams if they continue to hemorrhage points on that side of the ball.

Carlisle expressed his desire to amp up the Mavs' defense, per Callie Caplan in The Dallas Morning News.

“We just feel like we’ve got to bear down more defensively,” Carlisle said. “These next couple of games are against teams that are bigger and more physical, and they’re teams that rebound well, so we’ve just got to bring up our physical disposition and really concentrate on it more.

“[Upcoming opponents are] bigger, stronger, more physical, better rebounding, so it’s attitude, mindset, disposition,” Carlisle said. “We’ve got to bear down and pick it up.”

For example, the Mavs gave up 111 points in their road win over the Cleveland Cavaliers, a 2-4 team with a first-year head coach that is clearly in a state of rebuilding.

Dallas' starting backcourt doesn't exactly inspire confidence in their defending ability, with Jalen Brunson, Seth Curry, and Luke Doncic making up a weak first line of defense. And while one-time All-Star big man Kristaps Porzingis is an accidentally shot-blocker, the Latvian forward also has the tendency to foul frequently and has difficulty defending perimeter players.