Stonnington Crime Investigation Unit detectives are appealing for public assistance following an affray in Windsor last month.
Investigators have been told the victim was walking home when he saw a group of males assaulting a man near the intersection of Chapel and Victoria streets about 5.50am on Sunday 12 February.
When the victim tried to assist, the offenders turned on him.
It is alleged the victim was pushed to the ground and kicked to his head multiple times.
The offenders then fled on foot northbound on Chapel Street.
The 37-year-old victim from St Kilda was taken to hospital with facial injuries and concussion.
Investigators have released images of four men they believe may be able to assist with their enquires.
The men involved are all believed to be aged in their 20s.
Anyone with information is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppersvic.com.auExternal Link