Cooper Flagg was expected to be an NBA superstar in the making way before the Dallas Mavericks picked him with the No. 1 pick in the 2025 NBA Draft. There’s no telling how long it will take for him to become an elite player, but he definitely has the work ethic to become one.
His Mavericks teammate Klay Thompson acknowledged this when praising Flagg as a player. He definitely believes in the kind of player Flagg can be when he enters his prime.
What Did Klay Thompson Say About Cooper Flagg?
In an interview shared by the NBA’s official X account, Thompson has revealed what has impressed him most about Flagg since Dallas started its training camp.
“The thing I’m most impressed by with Cooper is he did not sit out one drill,” Thompson said. “He is in incredible shape, he’s got great stamina, and when he is in his mid-20s and fills out his physique, I mean, it’s going to be scary how great he can be.”
Though Thompson knows he’ll get better from here, he believes Flagg is good enough currently to help the Mavericks a lot.
“He’s only 18 years old, making a huge impact,” Thompson said. “I’m just excited for his future, but he can also help us so much right now.”
“The thing I’m most impressed by with Cooper… he did not sit out 1 drill.”@KlayThompson on his rookie teammate’s work ethic 💯
Coop, Klay and the Mavs play OKC at 8:30pm/et on NBA TV! pic.twitter.com/QubasD0qJP
— NBA (@NBA) October 6, 2025
Flagg will get ample opportunity to show out with the Mavericks. Kyrie Irving is still recovering from an ACL tear, and Irving has confirmed that there’s no official timetable for his return.
More than that, though, Anthony Davis has proven himself to be injury-prone throughout most of his NBA career. He only played in nine games for the Mavericks because of a left adductor strain he suffered during his debut and an eye injury that required offseason surgery.
If he gets hurt sometime this season, Flagg will get every opportunity to prove to Dallas that he is the cornerstone of their future. The more Flagg shows out for Dallas, the likelier the fans will get over the Luka Dončić debacle from this past February.
No one will know for sure what Flagg will be made of when the season starts, but it’s already a fantastic sign that he’s getting high praise from Klay Thompson. That goes beyond the fact that Thompson helped the Golden State Warriors win four titles during his 13 seasons there.
Thompson himself showed his strong work ethic when he had to miss two seasons due to an ACL and Achilles tear, yet came back strong to help the Warriors win the title in 2022. If he sees that same work ethic from Flagg, then the Mavericks are in great hands.
Dallas officially opens the 2025-26 NBA season on Wednesday, October 22, when the team hosts the San Antonio Spurs at 9:30 p.m. ET on ESPN.
