Mr Mercer said the man who originally approached the victim was a caucasian with a green bandanna covering his face, while the person who punched him was a caucasian with dreadlocks.
Another man in his twenties was walking from Manners Street up Boulcott Street when he was knocked to the ground by two men and robbed in a second attack at about 11:20pm last night, police said.
Witnesses saw the man being assaulted and came to his aid.
The offenders were believed to have followed the victim from Manners St, Mr Mercer said.
"The two robberies were reported as occurring at the same time in different locations, and the offender descriptions differ. While we are keeping an open mind about the offenders, the crimes do not appear to be linked at this stage," he said.
He appealed for information from those who helped the victim or saw either of the offenders in the second attack.
They were described as two Caucasian men in their mid to late thirties. One had long straight blonde hair, while another wore black straight-brimmed baseball cap.
- HERALD ONLINE