Police believe a knife found near a stabbing scene in Northmead, may have been used in the attack, last Friday.
On Friday, August 1, just after 6am, a 56-year-old man was stabbed in his leg while leaving work in Briens Road.
Police said a man, dressed in black, confronted him before a knife was thrown, penetrating his lower right leg.
Paramedics treated him at the scene before taking him to Westmead Hospital, from where he has since been discharged.
Police believe the attack was planned.
They have also found a knife near the scene which has been forensically examined.
Police appealed to anyone with any information which could help their investigation to contact Parramatta detectives on 9633 0799 or 9688 8499 or Crime Stoppers on 1800 333 000.