Voit is dealing with a biceps injury, Jeff Sanders of The San Diego Union-Tribune reports.
The injury explains why Voit is out of the lineup against the left-handed Tyler Anderson on Saturday. The extent of Voit's injury is not yet known, but manager Bob Melvin didn't rule out a trip to the injured list. Voit will undergo tests to determine exactly what type of issue he is dealing with, at which point his expected return date should become clearer.