The youngest player in the NBA played his first preseason game with the Dallas Mavericks on Monday night, and Cooper Flagg looked plenty comfortable at the highest level of professional basketball.
Flagg had an early warm-up against some of the best rookie and second year players during NBA Summer League, but Monday night’s preseason game against the returning champion Oklahoma City Thunder was his first chance to get game action with the Mavs main lineup.
And the 18-year-old from Newport, Maine wasted little time demonstrating his balanced approach on both sides of the floor.
Flagg was in the starting lineup for Dallas, and though he didn’t have any points in the first quarter, he quickly started hauling in rebounds and provided a block around the rim that launched an emphatic fast break alley-oop in transition for the Mavericks.
Dallas Mavericks forward Cooper Flagg, top, blocks a shot by Oklahoma City Thunder guard Isaiah Joe (11) during the first half of a preseason NBA basketball game in Fort Worth, Texas, Monday, Oct. 6, 2025. (AP Photo/LM Otero)
The Dallas rookie was quick to move the ball to teammates and also notched several early assists as the Mavericks built up a big lead over the Thunder.
“That’s why he’s so respected, he can do it all,” said Jamie Dixon, the head coach at Texas Christian University, who joined the Maverick’s TV broadcast for a few minutes during Monday night’s game.
After missing a couple of shots to start the game, Flagg unleashed a quick 10 points in the last five and a half minutes of the second quarter.
His first preseason points came on a driving layup where he went up and around a defender, which he quickly followed with his first three pointer. He added two free throws and then another three from beyond the arc.
Flagg finished the first half with 10 points, six rebounds, one block and three assists. He and other starters rested during the second half, and the Mavericks bench held on for a 106-89 win.
Flagg called his first preseason game “an incredible experience” in a post-game interview with Mavs TV. Sideline reporter Lesley McCaslin asked him about his strong finish to the second quarter.
“The game just slowed down,” Flagg said, adding that he was trusting the offense and trusting his shots.
He provided the kind of balanced stat line that Duke University fans got used to last year, when he led the Blue Devils in all five major statistical categories and won nearly every player of the year award in men’s college basketball.
Dallas Mavericks forward Cooper Flagg (32) laughs with center Dereck Lively II (2) and other teammates during the NBA basketball team’s media day in Dallas, Monday, Sept. 29, 2025. (AP Photo/LM Otero)
And while most top NBA draft picks land with teams that are struggling or rebuilding, Flagg wound up on a Dallas team that is just two seasons removed from an NBA Finals appearance. Dallas’ unlikely draft lottery win despite just a 1.8 percent chance means Flagg starts his NBA career around an established roster with several NBA champions, including big man Anthony Davis.
“For him, he’s coming to a team that’s established,” Davis said about Flagg, as reported by the Athletic. “We have veteran talent. He doesn’t have to do as much as a normal No. 1 pick has to do. We are still going to ask him to be Cooper Flagg for sure. But the pressure is not going to be on him as much as a usual No. 1 pick who is going to one of the worst teams in the league.”
Dallas will play three more preseason games before opening its regular season on Oct. 22 against the San Antonio Spurs.