Police in Tayside are now appealing for information after the serious assault happened around 6.55pm on Monday, 22 March on Leonard Street, Arbroath.
The 50 year-old was struck with a weapon by another man and taken to Ninewells Hospital after sustaining serious injuries to his head.
The suspect is described as having a Glasgow accent and shaved hair.
He was wearing a blue hoodie, a red t-shirt and black tracksuit bottoms.
Detective Sergeant Craig Kelly, of Dundee CID, said: “We are appealing for information from members of the public to help trace those involved.
“We would urge anyone who may witnessed the incident or saw someone acting suspicious in the area before or after the incident to contact police.
“Anyone with any information is asked to contact police on 101 quoting incident number 3115 of 22 March.”