The Thunder fear that Holmgren suffered significant ligament damage in his right foot, Shams Charania of The Athletic reports.
Holmgren suffered the injury while trying to stop LeBron James on a fast break during a Pro-Am game Saturday. The rookie didn't return to the contest before it was eventually called off due to poor court conditions. Per Charania, exams have shown Holmgren has potential torn ligaments, but a return timetable is still being determined based on further evaluations.