By letter filed with the municipal clerk the manager shall designate a qualified municipal administrative officer to exercise the powers and perform the duties of manager during his temporary absence or disability.

In the event of the failure of the manager to make such designation the municipal council may by resolution appoint an officer of the municipality to perform the duties of the manager until he shall return or his disability shall cease.

During such absence or disability, the council may revoke such designation at any time and appoint another officer of the municipality to serve until the manager shall return or his disability shall cease.