Detectives are keen to trace the man pictured within the CCTV footage, who was seen to be in the area at the time of the incident, which happened on January 29 at around 12.10am.
He is described as a white, of medium build, between 5 foot 8 and 5 foot 10 inches tall, in his late 20s or early 30s, with short dark receding hair and a Scottish accent.
The male was wearing light denim jeans and a grey jacket. with a white or light grey rucksack over both shoulders.
He had a white Staffordshire bull terrier with a brown or black spot on the base of its tail.
DC Christopher Harding from Gayfield CID said: “The victim was on a night out with friends and was subjected to an assault during which he suffered a significant injury.
“The man pictured is believed to be of significance to our investigation, and anyone who can assist in tracing him is asked to come forward. Similarly we would ask this man to get in touch and help with our investigation.”
Those with information can contact Police Scotland on 101 or the charity Crimestoppers in complete anonymity on 0800 555 111.