How Cooper Flagg Fared in NBA Debut in Mavericks’ Opener vs. Spurs

Cooper Flagg and the Mavericks were blown out by the Spurs in his NBA debut.

Rookie Cooper Flagg made his debut for the Mavericks on Wednesday. / Kevin Jairaj-Imagn Images

Cooper Flagg made his NBA debut on Wednesday, taking the floor as the Mavericks faced the Spurs at the American Airlines Center.

Despite playing small forward at Duke and standing 6'9", Flagg made his debut in the starting lineup at point guard. Mavericks coach Jason Kidd noted back in June that he wanted to use Flagg at point guard, which gives them an opportunity to boast the league's biggest team.

"I want to make him uncomfortable and see how he reacts being able to run the show," Kidd said of Flagg playing point guard in June. "Being able to play the 2, play the 3, he's comfortable playing that. But we want to push, and I think he's going to respond in a positive way. It's all right to fail, it's all right to turn the ball over."

Flagg immediately got the game started with a steal and nearly cashed in on a thrilling alley-oop from Anthony Davis, but was unable to get the ball into the net. Davis ended up cleaning up with a bucket off the rebound.

Cooper Flagg almost had the greatest first bucket in NBA history pic.twitter.com/LkwiVmcPhd

— BetMGM 🦁 (@BetMGM) October 23, 2025

After that, it was a slow start for Flagg, who attempted just two shots in the first half, missed both, and finished the half with six rebounds and no points over 17 minutes of action. At another point in the first half, Spurs' Stephon Castle forced a turnover on Flagg and ran it the other way for a basket.

In the second half, Flagg quickly made his first career basket on a jumper. He seemed to get in a better rhythm late in the third quarter with back-to-back baskets. Flagg ended up finishing with 10 points on 4-of-13 shooting to go along with 10 rebounds and one steal across 32 minutes—good for his first NBA double-double. Flagg hit both of his free-throw, missed his lone three-point attempt and committed three turnovers.

Cooper Flagg's first NBA points 🔥

Start of a new era in Dallas 🔵 pic.twitter.com/ZjRQAeHSMH

— ESPN (@espn) October 23, 2025

The hyped No. 1 pick saw his first professional action, but the Spurs' young trio of top-five picks Victor Wembanyama, Stephon Castle and Dylan Harper stole the show—especially Wembanyama, who was dominant in his return and their 125-92 win over the Mavericks. Wembanyama notched 40 points, 15 rebounds and three blocks, while Castle and Harper combined for 37 points.

It was far from the storybook start for the Flagg era in Dallas, and there will be plenty for Mavs rookie to learn from this loss as they prepare for their next game against the Wizards.

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