The Dallas Mavericks faced the Boston Celtics at TD Garden on Friday night in a game that carried personal significance for rookie forward Cooper Flagg. While Dallas lost 120-100, the night meant more than the score for the 19-year-old Maine native, who played his first professional game in Boston against someone he's idolized for years, Jayson Tatum.
Flagg, the No. 1 overall pick in the 2025 NBA Draft, received an unusual reception during pregame introductions. Boston fans, who typically boo opposing starters at TD Garden, instead greeted the rookie with loud cheers. The reaction surprised Mavericks head coach Jason Kidd. Flagg had numerous family members and friends from Maine in attendance for the homecoming game.
Facing Tatum added emotional weight to the matchup. Flagg grew up watching the Celtics and followed Tatum’s development closely, including his college career at Duke Blue Devils under coach Jon Scheyer. Flagg also played one season at Duke before entering the NBA.
“It was incredible. There's so many levels to it,” said Flagg when asked about playing against Tatum after the game. “He's somebody that I idolized growing up, watching him go through levels and ranks. I watched him at Duke, and kind of to follow in his footsteps and play for [Jon] Scheyer, and then obviously coming into the league is just surreal. It was really special for me to have this experience tonight.”
Cooper Flagg on the reception from the Boston/Maine crowd/sharing tonight with Jayson Tatum:
“There’s so many levels to it. He’s somebody I idolized growing up…Watched him at Duke & have been following his footsteps..It’s surreal. It’s really special just for me to have this… pic.twitter.com/jq2CMbYptK
— Mike Curtis (@MikeACurtis2) March 7, 2026
The rookie finished with 16 points, eight rebounds, and six assists in 30 minutes, but his efficiency wasn’t there, shooting 7-for-23 from the field and 0-for-4 from three-point range. He also committed three turnovers and had a minus-17 rating. The performance came just two games after returning from an eight-game absence caused by a left midfoot sprain and on the second night of a back-to-back.
Although his numbers were modest, Flagg continues to carry a heavy workload for Dallas. The 6-foot-9, 205-pound forward frequently operates as the team's point-forward, with many offensive sets running through him despite the Mavericks' 21-42 record.
Tatum's return to action was another major storyline. Playing his first game since rupturing his Achilles tendon last May, he ended the night with 15 points, 12 rebounds, and seven assists in 27 minutes, shooting 6-for-16 from the field.
Up next, the Mavericks will travel to Toronto to face the Raptors on Sunday, while the Celtics will visit Cleveland to take on the Cavaliers.
