The severity of the injury was learned after Markkanen underwent the MRI at Rush University Medical Center in Chicago on Thursday.
It is not known how long Markkanen has been dealing with the injury.
Markkanen recorded 21 points in 34 minutes as the Bulls posted a 117-110 win against the Minnesota Timberwolves on Wednesday.
The 22-year-old Finn is averaging 15.0 points and 6.5 rebounds in 46 games this season. He is averaging 16.2 and 7.7, respectively, since being the seventh overall pick of the 2017 NBA Draft.
–Field Level Media