Matt MacKenzie, Cooper Flagg’s personal trainer, mentor and skills coach, said winning Rookie of the Year was one of the Newport native and Dallas Mavericks star’s individual goals for the season.
Earlier this week, Flagg reached that by narrowly beating out former Duke teammate Kon Knueppel for 2025-26 NBA Rookie of the Year.
“I’m happy he was able to check that off,” MacKenzie said. “He was excited about it.”
MacKenzie, who owns Eastern Maine Sports Academy and Results Basketball in Veazie, said Flagg exceeded the expectations placed on him from the start, after being picked No. 1 overall in the NBA Draft.
“He was matched up against the opposing team’s best defender night in and night out and he was still able to perform at a very high level,” MacKenzie said. “Even though the team didn’t have the success it was hoping for, Cooper’s individual success was off the charts, and his versatility was able to shine through in most every statistical category.”
The 6-foot-9-inch, 220-pound Flagg finished his season averaging 21 points, 6.7 rebounds, 4.5 assists, 1.2 steals and 0.9 blocks per game and was the only member of the 2025 draft class to rank in the top five in scoring, rebounding, assists, steals and blocks.
The 19-year-old Flagg became the first player since Hall of Famer Michael Jordan to lead his team in points, rebounds, assists and steals in the same season. And that includes non-rookies as well as rookies.
His 51 points in a game against Orlando made him the youngest player in NBA history to score 50 points in a game and when he scored 45 against the Lakers two nights later, he became just the second rookie to combine for at least 96 points during a two-game span.
Hall of Famer Wilt Chamberlain was the other one.
After the All-Star break, he averaged 22.6 points, 6.9 rebounds, 5.4 assists, 1.2 steals and 1.2 blocks and was the only player in the league to average 20-6-5-1-1.
Knueppel averaged 18.5 points and 5.3 rebounds per game on the campaign but managed just 10.8 ppg and 4.5 rpg over his last six games.
“The end of the season certainly solidified who was most worthy of that award,” MacKenzie said. “Our circle would never root against another player, especially somebody like Kon who we have a tremendous amount of respect for as a player and as a person. But the way Cooper finished versus the way Kon finished kind of solidified the award for him.”
Flagg played in 70 of the Mavericks’ 82 games with foot and ankle injuries sidelining him for 12 contests.
“It would have been very easy, especially with the team out of the playoff picture, to shut it down and focus on next season. But he didn’t want to go out that way,” MacKenzie said. “He didn’t want his season to end like that. He was dialed in on his recovery to make sure he could go out and perform for his team as soon as possible, and we all saw that during the last stretch of the season. He was back to himself and playing the way we saw him playing in January.”
Load management has become common in the NBA, where healthy players sit out games to preserve longevity and reduce the risk of injury. But it can be controversial because it deprives fans the opportunity to see players they want to see.
MacKenzie said that Flagg made it clear early on that he wanted to play all 82 games and that he only sat out when he had to due to injuries.
“He is one of those guys who understands that he has fans all over the country who want to watch him play, and he feels obligated to be at his best every single night,” MacKenzie said “He knows young fans may only get one chance to see him play, and for them and their families, it’s a lot of money to spend.”
MacKenzie noted that Flagg also wanted to give the Dallas fans something to look forward to and be positive about.
“They’ve gone through a lot in that city with Luka [Doncic] being traded [to the Lakers], the general manager [Nico Harrison] getting fired early in the season as well as AD [Anthony Davis] being traded,” he said. “Cooper did a really good job giving the fan base something to be excited about.”
This offseason, Flagg will divide his time between Maine and his new home in the Dallas area. His focus will be on bulking up and refining his skills, MacKenzie said.
“Number one, he wants to make sure he continues to develop his body and he plans to do that through the weight room and his diet,” MacKenzie said. “I expect him to go into next season with 10 pounds of additional lean muscle.
The other part is improving his craft as a basketball player, including “his ability to get to the spots he wants to get to on the floor whenever he wants to in late-clock, late-game situations,” MacKenzie said. “And he wants to continue to improve his confidence knocking down 3-pointers with higher efficiency.”
Flagg shot 46.8 percent from the floor this past season but just 29.5 percent beyond the 3-point arc.
Flagg played a number of positions for the Mavericks, who were beset by injuries and wound up 26-56. He saw some time as a point guard, and even though that is not his natural position, MacKenzie said in the long run, that will help him become that much better.
“He had the ball in his hands a lot, and he had to go through some highs and lows and some of his weaknesses and failures got exposed early on. He was put into positions where he had to adapt and overcome some challenges. In terms of overall learning experience, it was very beneficial,” MacKenzie said. “He has a natural playmaking ability, which gives him the ability to make the players around him so much better.”
