Traditionally, the marquee game on the opening night of summer league features the No. 1 and No. 2 overall picks from the draft playing against each other, but not this year. The NBA scheduled a matchup with Flagg squaring off against the son of the league's all-time leading scorer, LeBron James.

There were several notable faces sitting courtside to take in the Mavericks’ summer league opener. Mavs Governor Patrick Dumont sat across from the Dallas bench. He was joined by a bevy of key members from the varsity group, including Kyrie Irving, P.J. Washington, Max Christie, Naji Marshall, Jaden Hardy and Olivier-Maxence Prosper.

Cooper Flagg strolled into UNLV's Thomas and Mack Center at 4:17 p.m. for his Summer League debut, wearing Dallas Mavericks gear, bright white New Balance shoes, and an emotionless look on his face as he passed through security.