Dallas Mavericks rookie Cooper Flagg described his NBA Summer League debut as "one of the worst games of my life," but drew praise from coaches and opposing guard Bronny James after a win over the Los Angeles Lakers.

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.

Rookie Cooper Flagg may not have been happy with his professional debut Thursday night in the NBA Summer League, but he still drew rave reviews all around after the Dallas Mavericks defeated the Los Angeles Lakers,

The Dallas Mavericks started Las Vegas Summer League with an 87-85 win over the Los Angeles Lakers Thursday night. Undrafted rookie Ryan Nembhard led Dallas with 21 points and five assists. Cole Swider scored 22 for LA in defeat.

Cooper spent his entire NBA career with the Lakers, appearing in 873 regular-season games with the franchise. Though Cooper was mostly utilized in a reserve role, that didn’t stop him from being a key piece in a Lakers organization that won plenty of titles during the 1980s.