Doncic was tossed from Saturday's affair against the Indiana Pacers in the third quarter after kicking a basketball into the crowd. It was the 19-year-old's second technical foul of the game after receiving one in the first half.
Doncic claims he had no idea that performing such an action would result in his removal from the game.
"I didn't try to kick the ball out of the stands," Doncic told reporters postgame, per FOX Sports Southwest. "I didn't know the rule (is) if it goes to the stands, you get ejected ... it's different rules in Europe, so I didn't know that was a rule."
Doncic asserted he wouldn't have been ejected if he had done the same thing in a European league but ultimately accepted responsibility for his actions.
"I know it was my fault," Doncic said. "I learned a new thing today."
Head coach Rick Carlisle spoke with Doncic about the incident and used it as a teaching moment.
"We talked about it after the game and basically pointed out the important aspects of why those situations got to be avoided for all of us, not just him," Carlisle said, according to team reporter Dwain Price.
The NBA Video Rulebook states: "Players are not permitted to intentionally throw, kick, or send the ball into the stands for any reason. Any violation of this rule results in a technical foul. Note also that if the ball enters the stands with force, the player would also be ejected from the game."
It was a rough night all-around for Doncic, who finished with eight points on 3-of-14 shooting. He's averaging 20.0 points, 6.7 boards, and 5.1 assists through 44 games this season.