The Bulls issued a statement Tuesday acknowledging that forwards Nikola Mirotic and Bobby Portis were involved in a physical altercation during practice that left Mirotic with a concussion and maxillary fractures.

“Chicago Bulls forwards Bobby Portis and Nikola Mirotic had a physical altercation during today’s practice. As a result of the incident, Mirotic suffered a concussion and maxillary fractures. Surgery is likely required. Mirotic is out indefinitely. The Bulls are evaluating disciplinary action. An update will be provided when applicable.”

Mirotic was briefly hospitalized following the altercation with Portis. Mirotic stayed down for several minutes after the scuffle, early estimates on the injuries sustained from the altercation will keep him sidelined “a few weeks” following surgery.

A source who spoke to Mirotic after he was released from the hospital said the forward suffered two fractures and placed an early estimate for his absence at “a few weeks, at least.” He possibly will have to wear a mask upon that return.Mirotic left European basketball in 2014 to join the Bulls and resigned with the team this offseason. He has been teammates with Portis since 2015. Portis was selected with the 22nd overall pick in the 2015 NBA Draft by the Bulls. Reportably, the two players have been going at it for quite some time . This has been three years in the making, a source said. Mirotic has broken bones in his face, apparently instigated, and Portis punched him.Mirotic averaged 10.6 points and 5.5 rebounds while knocking down 41.3 percent of his shots last season. Portis averaged 6.8 points and 4.6 rebounds off the bench in his second season in the NBA. It remains to be seen if Portis or even the injured Mirotic will be suspended by the team for their disciplinary actions.