Cairns import Tony Mitchell's season-long NBL ban for throwing the ball at a referee has been reduced to 10 matches on appeal.

The American was last month found guilty of deliberately throwing the ball at referee Vaughan Mayberry when the Taipans were eliminated from the NBL finals by eventual champions Perth.

Mitchell did not attend his appeal hearing having returned to the United States, but the league's tribunal ruled the original punishment was excessive.

The 27-year-old forward has apologised for the incident, admitting his conduct was unacceptable.

"I let my emotions get the best of me following my team's loss," he said in a letter addressed to the NBL, the Taipans and fans.

"There is no excuse for my behaviour. Please accept my apology and know that it will never happen again in the future."

It was the former NBA D-League player's 10th game with the Taipans, having signed only last month with the club. In making its original decision.

NBL tribunal chair Tony Nolan QC ruled that while Mitchell had not intended to hurt the official and the force was not significant enough to cause injury, the act was serious enough to justify the penalty.

The new ruling takes into account his apology.

If Mitchell is re-signed by the semi-finalist Taipans, he could be back playing in the NBL by November this year.

He averaged a little more than eight points a game in his 2016/2017 NBL stint.