Cooper Flagg is set to make his Dallas Mavericks debut on Monday as the team tips off its preseason against defending champions, the OKC Thunder. Flagg has been cleared to play and is expected to start alongside Anthony Davis, D’Angelo Russell, Klay Thompson and Dereck Lively II.Selected with the No. 1 overall pick, Flagg represents the Mavericks’ new era following the midseason departure of superstar Luka Doncic last year. With immense potential, the rookie would be eager to show why he is considered one of the top talents in the league.Flagg has spent the offseason in the gym and has been building chemistry with his teammates since the start of training camp. On Sunday, the 6-foot-9 rookie was seen working on his 3-point shot after practice, while videos of his pick-and-roll plays with Anthony Davis have excited Dallas fans.How did Cooper Flagg fare in 2025 NBA Summer League?Cooper Flagg struggled to make an impact in his NBA Summer League debut against the LA Lakers, failing to live up to expectations. However, in his second outing against the Spurs, the Dallas Mavericks rookie showcased his impressive size, athleticism, shooting mechanics and ball-handling skills.Overall, the former Duke phenom played two games and averaged 20.5 points in 31.4 minutes per contests. He averaged 5.0 rebounds, 2.5 assists, 1.5 steals and 1.0 block while shooting 36% from the floor, including 21% from beyond the arc.How to watch Cooper Flagg in action during Mavericks vs. Thunder preseason game?The preseason game between the Dallas Mavericks and OKC Thunder will take place on Monday, Oct. 6, at the Dickies Arena in Fort Worth, Texas. Tip off is slated for 8:30 p.m. EST (5:30 p.m. PT).The Mavericks vs. Thunder game will be broadcast live on NBTV. Live streaming will be available on the NBA League Pass and Fubo.