Cooper Flagg's standout rookie season ends as the No. 1 pick of the Mavs injures ankle in finale

DALLAS — Cooper Flagg's standout rookie season ended slightly prematurely after the No. 1 pick of the Dallas Mavericks limped to the locker room in the finale against Chicago and was ruled out with an ankle sprain Sunday night.

Flagg winced as he left the court favoring his left ankle in the second quarter, and the Mavs soon said he wouldn't return. The 19-year-old is in a tight race with former Duke teammate Kon Knueppel for Rookie of the Year.

It wasn't immediately clear how Flagg was injured. He had 10 points and four rebounds in 10 minutes before leaving the game. He will finish the season averaging 21.0 points, 5.4 rebounds and 4.5 assists in 70 games.

The Mavericks have been out of the playoff race for weeks in a season that started with high expectations but crumbled with Anthony Davis' continuing injury issues and eventual trade to Washington. Davis' absence led to the team keeping Kyrie Irving sidelined the entire season after the star guard tore the ACL in his left knee in March 2025.

Despite the steady slide in the standings, Flagg kept making history, capped by a 96-point outburst in two games over the second-to-last weekend, including the 51 against Orlando that made him the first NBA teenager to score at least 50 in a game. He broke his own record of 49 for a teenager.

Flagg led Duke to the Final Four a year ago as just the fourth freshman to be named The Associated Press men's basketball player of the year.

The accolades kept rolling in after the Mavs converted just a 1.8% chance to win the lottery and won the rights to draft him.

Flagg and Michael Jordan are the only two rookies to record multiple games of at least 45 points since the NBA-ABA merger in 1976-77.

Flagg was playing against LeBron James and the Los Angeles Lakers earlier this month when he scored 45 points and passed the 41-year-old for the most 40-point games by a teenager with his fourth.