A medical examiner has determined Zeke Upshaw, a swingman for the Detroit Pistons' G League affiliate, suffered a "sudden cardiac death" after collapsing on the court.
WOOD-TV reports Kent County medical examiner Dr. Stephen Cohle conducted an autopsy Tuesday, though the investigation will continue for a few weeks.
The 26-year-old Grand Rapids Drive guard collapsed Saturday during a game against the Long Island Nets, and died Monday.
Cohle says he observed some "cardiac abnormalities," and he's working to determine the exact type of heart disease.
Upshaw, a Chicago native who played for Illinois State and Hofstra, was undrafted and played internationally in Slovenia and Luxembourg.
He spent most of the last two seasons with the Drive, appearing in 75 games primarily as a reserve and averaging 7.6 points.