Erik Spoelstra says the one thing he can't believe about Mavericks' Cooper Flagg

Cooper Flagg led the Mavericks to an upset win over the Miami Heat on Wednesday night.

Dec 3, 2025; Dallas, Texas, USA; Dallas Mavericks forward Cooper Flagg (32) reacts against the Miami Heat during the second half at American Airlines Center. Mandatory Credit: Kevin Jairaj-Imagn Images | Kevin Jairaj-Imagn Images

The Dallas Mavericks upset the Miami Heat on Wednesday night with a 118-108 win. Cooper Flagg led the way, scoring 22 points on an efficient 9/13 shooting, adding in six rebounds, two assists, a steal, and a block. It was his third straight game scoring at least 20 points, making him the youngest player in NBA history to do so, as he's coming off games with 11 assists against the Lakers, 35 points against the Clippers, and 24 points against the Nuggets.

That'd be impressive for any player to have a run like that, much less an 18-year-old who should still be a freshman in college right now. He's becoming more and more comfortable with every game, and that's impressing a lot of people.

One such person is Erik Spoelstra, the head coach of the Miami Heat, who has come away blown away from the rookie in these two games.

"I said it in Miami, he just has a great maturity about him," Spoelstra said after Wednesday's game. "He's not even 19 years old. I just can't fathom... it just doesn't make sense. And if I was 18... I would stat hunt up and not play the right way. He just has a great competitive spirit, plays the right way competes to win. You know, that's an extremely hard thing to teach young players."

Heat coach Erik Spoelstra on Cooper Flagg, Ryan Nembhard and Max Christie:

“He’s not even 19 years old, I can’t even fathom that. … If I was 18 in his shoes, I would stat hunt.” pic.twitter.com/FyvjeZikvC

— Ron Harrod Jr. (@RonKnowsSports) December 4, 2025

READ MORE: Cooper Flagg, Ryan Nembhard make NBA history in Mavericks' win over Miami Heat

Impressive Start to an NBA Career for Cooper Flagg

Flagg had a weird start to his career because he was being asked to play point guard, but he's been much better alongside just any other point guard in general, but especially Ryan Nembhard. Nembhard has been a revelation for this team, as the two highest offensive rating games for the team with the season have come with Nembhard in the starting lineup.

And Flagg has just been living off of the way Nembhard is setting people up. It's been back-to-back games of double-digit assists for Nembhard, and arguably no one has benefitted more than Flagg. The spacing is better, the pace isn't as chaotic, and Nembhard is just able to direct traffic in a way that no one else has for the Mavs this year.

Flagg was named the Western Conference Rookie of the Month this week, and he's averaging 17.3 PPG, 6.6 RPG, 3.3 APG, and 1.4 SPG. He's picking and choosing his spots efficiently, he's getting more confident finishing around the basket, and his defense is great. If he ever develops his three-point shot, the ceiling really is limitless.

READ MORE: 3 overreactions as Mavericks down Heat, establish three-game winning streak

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