Melbourne football manager Josh Mahoney told AFL.com.au Michie had copped a bump to his jaw against Essendon's VFL team at Windy Hill, with scans on Monday revealing a small crack of the jaw.
Michie also suffered a cracked wisdom tooth in the incident.
"Viv will have surgery tonight and is expected to miss four weeks of football," Mahoney said on Monday.
"This is a disappointing setback for Viv, who had displayed some good form during early parts of the year."
Michie joined the Demons from Fremantle in last October's trade period after playing one game in three seasons with the Dockers.
The 22-year-old played Melbourne's opening two games this year, but was dropped after the 93-point round two loss to West Coast.
