There's a lot of hype among fans and the media regarding Cooper Flagg's upcoming rookie season with the Dallas Mavericks. He's touted to be one of the best first-year players in the NBA. While people have shown excitement for Flagg, ESPN's Marc Spears believes the league hasn't done enough to promote the youngster.There has been a lot of talk about Flagg being a generational player. At 6-foot-9, he's shown great control and maturity on the floor. Before he was even drafted into the NBA, the small forward displayed his talents against some of the best players in the world. The Mavericks rookie stole the show in 2024 when Team USA played against the USA Select Team ahead of the Paris Olympics.Even with that, there haven't been a lot of promotions by the NBA regarding the former Duke star, despite being the No. 1 of the 2025 draft. Spears called out the league for it during Monday's episode of ESPN's "NBA Today.""NBA, what are you doing? Why aren't you promoting this guy?" Spears said."Get on the train, this dude is gonna be a star... He should be in all the promotions, I don't see him... Nobody's talking about this guy, they're making a mistake... Don't sleep on this kid."Mavericks fans are looking forward to seeing how Cooper Flagg will fare in his first professional season. On Monday, the forward is expected to play in his first preseason game against the OKC Thunder at Fort Worth.According to Flagg, he's excited to be on the floor with his teammates and develop chemistry early in the year.Mavericks stars spoke highly of Cooper Flagg ahead of his first preseason gameCooper Flagg became viral as soon as the Mavericks started their training camp. Fans loved the way he was active on the floor during scrimmages. Ahead of the team's preseason game against the Thunder, star forward Klay Thompson revealed that Flagg participated in every drill in preparation for the new year.“Cooper did great,” Klay Thompson said. “I’m most impressed he didn’t sit out one drill. I don’t care how many shots he misses or mistakes he makes. The fact that he’s in there and competing every single drill — that’s what impresses me.”All-Star big man Anthony Davis has noticed how Flagg has absorbed the pace of the professional setting. Davis said that the young player has grown comfortable.“He looks comfortable,” Davis said. “He can block shots and he can jump, he can rebound. He can defend one through five. I had some conversations with him. I didn’t have vets like he does — like with myself, Klay, Caleb, Kyrie — where you can go to them and talk.”Cooper Flagg's official NBA debut will be on Oct. 22 against the San Antonio Spurs.