Coach Fred Hoiberg confirmed the front office's decision Wednesday night, saying Mirotic was with the team for its game in Portland but was sent back to the hotel prior to tipoff.
"I got a call today, and the decision was made to not play Niko tonight," Hoiberg said. "That's all I know at this point. We will reassess tomorrow."
The Bulls thought they had a deal done Tuesday that would have sent Mirotic to the New Orleans Pelicans, but Mirotic and his representatives nixed the arrangement, according to a source, because the $12.5 million team option for the 2018-19 season would not be guaranteed.
The Pelicans and Bulls were trying to finalize a package that included Omer Asik and a future first-round pick going to Chicago, league sources told ESPN's Adrian Wojnarowski. Asik is owed nearly $25 million through the 2019-20 season.
Mirotic signed a two-year deal with the Bulls in August.
Mirotic has thrived with the Bulls since missing the first 23 games of the season after a scuffle in practice with Bobby Portis left him with facial fractures and a concussion.