Chicago Bulls forward Nikola Mirotic has been hospitalized and is out indefinitely after a fight with teammate Bobby Portis at Tuesday’s practice, according to Shams Charania of Yahoo! Sports.

Portis reportedly struck Mirotic in the face with an alleged “cheap shot” following a shoving match during practice. Mirotic suffered a fractured bone in his face and sustained a concussion, according to the team. He could need surgery. The two veterans had been vying for minutes in Chicago’s rotation.

Mirotic, entering his fourth season with the Bulls, just signed a two-year, $27 million extension during the offseason. Portis is entering his third year in the NBA after being selected with the No. 22 pick in the 2015 draft.

Mirotic was expected to be the starter at power forward when the Bulls opened the season on Thursday against the Raptors. An early estimate has Mirotic sidelined for a “few weeks” while he recovers, according to KC Johnson of the Chicago Tribune. There has been no word yet on discipline for Portis.

Chicago is widely viewed as one of the league’s worst teams after trading Jimmy Butler in the offseason. The team does have another option at power forward in rookie Lauri Markkanen if Mirotic is out for an extended period.