"Both players owned responsibility in the incident itself but only one player threw a punch", Paxson told reporters Wednesday.
Both players will not travel with the team to Toronto for the regular season opener on Thursday night, which means the start at power forward will go to rookie Lauri Markkanen.
Before the incident, Mirotic was likely to be the Bulls' leading scorer in 2017-18, not because the career 10.8 points-per-game scorer was ready to elevate his game, but because the Bulls are that bad thanks to a series of bewildering trades ostensibly created to rebuild the franchise that instead yielded startlingly unimpressive hauls. He's a good kid, he's a competitive kid. "And as we all know when you make mistakes, you have to suffer the consequences".
The two players had been talking trash to one another in practice, going back and forth before those exchanges escalated into a physical encounter, league sources told ESPN's Adrian Wojnarowski.
The suspension came after Portis and Mirotic got into it during a practice on Tuesday and ended with Portis laying out Mirotic with a single punch that broke multiple bones in Mirotic's face and gave him a concussion. Portis then dropped Mirotic with a punch that floored him for several minutes before he got up. He was taken to the hospital and released later Tuesday. He finally prolonged his time with the Bulls, signing a two-year contract worth 27 million dollars.
Portis, also a forward, averaged 6.8 points for Chicago last season.