Cooper Flagg called his NBA Summer League debut “one of the worst games of my life” after shooting 5-of-21 from the field.

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.

The Cooper Flagg era unofficially began Thursday night when the Dallas Mavericks opened the Las Vegas Summer League with an 87-85 win over the Los Angeles Lakers. Here are five observations from Flagg’s debut in Thursday’s win over the Lakers: Center of attention: Flagg vs.