Butler coach Brad Stevens said Howard suffered the concussion and wound in Monday night's game against Illinois-Chicago.
Howard leads Butler (16-9, 8-5 Horizon) in scoring (17.1 ppg) and rebounding (7.8).
Team doctors made the decision Wednesday night to hold Howard out against Wright State. The decision was based, according to Stevens, on concern about the concussion and the possibility of symptoms showing up days after the initial blow.
It is Howard's second concussion in less than a year.
Stevens said the best-case scenario for Howard returning to the lineup is Saturday night at home against Detroit.