A 15-year-old boy suffered a minor cut on his stomach after an altercation in Parkhill Plaza on Tuesday 31 October.
Police responded to an armed robbery call at 5.45 p.m. on Halloween night, where they arrested and questioned a 17-year-old boy related to the incident.
The Narre Warren boy was released pending further inquiries.
According to Ambulance Victoria, the victim was taken to Casey Hospital on the same night and is in a stable condition.
Multiple workers from the shopping centre confirmed that at least five assailants were chasing after the victim.
Similar accounts from bystanders recalled all parties going into Coles and causing a commotion before leaving.
While unconfirmed, other witnesses reported having seen a knife, or multiple knives from the assailants.
Detectives are still investigating if a stabbing occurred, with any witnesses urged to contact Crime Stoppers at 1800 333 000 or make a report online at www.crimestoppersvic.com.au.