If the Village Manager temporarily is unable to perform the duties of the office, the Village Manager may appoint a temporary successor to act as acting Village Manager to perform the duties of the office for a period of 15 days or less, and may appoint a temporary successor for a longer period with the approval of the Board of Trustees. If a permanent vacancy occurs, the vacancy shall be filled in accordance with the appointment procedures set forth in § 31.05 of this code.