He was punched twice in the face during the incident at about 6.15 pm last Sunday.
A woman intervened, telling the man to stop, before they both got into a white Renault hatchback and drove off.
The attacker is described as mixed-race, aged around 50, and about 6ft tall. He was of stocky build and had dark and grey hair.
The woman is described as white, aged around 45 to 55, about 5ft 9ins tall, of slim build and with shoulder-length blonde hair. Anyone with information is being asked to phone the States police on 612612 or Crimestoppers on 0800 555 111.
