The NBA wants to reduce the time players spend with pregame handshakes and rituals that have become increasingly prevalent in recent years.
Players must be ready for tipoff 90 seconds after player introductions are finished.
"There's a 90-second countdown, it is placed on the clock," NBA spokesman Tim Frank said. "At 30 seconds, there's a warning horn and alert by the refs. At the end, teams need to be ready to tip off or face a delay-of-game warning."
Games have routinely taken five minutes or longer to begin after the starting lineups were announced.
"I personally don't like it," Kevin Durant told The Oklahoman. "Every player in this league has routines they do with their teammates, rituals they do before the game and before they walk on the floor. The fans enjoy it. You see the fans mimicking the guys who do their stuff before the game. To cut that down really don't make no sense."