Watch: Flagg family shares heartfelt messages after Cooper wins Rookie of the Year

Kelly Flagg, right, and her husband Ralph, listen to their son, Duke forward Cooper Flagg, Associated Press Player of the Year, during a news conference ahead of the Final Four college basketball games in the NCAA Tournament Friday, April 4, 2025, in San Antonio. (AP Photo/Eric Gay) (Eric Gay/AP)

Cooper Flagg took the NBA by storm in his first season in the league to the tune of winning the Rookie of the Year award on Monday night.

He'll be the first to tell you, though, that he didn't do it alone.

Shortly after the announcement naming Flagg as the league's top rookie, the Dallas Mavericks social media team shared a video featuring the Flagg family: mom Kelly, dad Ralph and twin brother Ace, along with Flagg's personal trainer Matt McKenzie. In it the four share heartfelt messages to Flagg following his stellar rookie season.

"Congratulations, bud," Kelly Flagg says in the video. "I never doubted that you could do it. The growth and maturity that you've shown day in and day out through this process, through this grind, is absolutely incredible. I couldn't be any prouder."

Flagg also received shoutouts from Mavericks legend Dirk Nowitzki and from fellow No. 1 overall pick in Wings guard Paige Bueckers on Monday night, to add to the heap of praise the 20-year-old sensation received.