According to the NBA Academy website, the players in these academies range from 14 to 18 years old. Tatum told ESPN that officials in the N.B.A.’s New York office, including Commissioner Adam Silver, were not aware of broad mistreatment of players. In Xinjiang, the N.B.A. “didn’t have the authority or the ability to take direct action against any of these local coaches,” Tatum said.