Another person believed to be in the home at the time escaped without injury.
Neighbours have claimed they heard three shots fired, according to reports.
Police have created a crime scene at the address, and the man has been taken to hospital for treatment.
The Victoria Police statement called for anyone with information about the shooting to contact Crime Stoppers on 1800 333 000 or make a confidential report at www.crimestoppersvic.com.au.
"Serious Crime Response Team detectives are investigating the circumstances surrounding a firearms incident which occurred in Ascot Vale early this morning," the statement said.
"Emergency services were called to a Gillespie Ave home after receiving reports that a man had been injured in a shooting at 2.20am.
"The 52-year-old man suffered a graze injury to his forehead after several shots were fired at the front of the house.
"There was one other person in the house at the time of the incident but they were not injured.
"The man was conveyed to hospital and a crime scene has been established."
No arrests have been made and the investigation is ongoing.
The disgraced exercise scientist is banned for life from the NRL and AFL.
The AFL Anti-Doping Tribunal last year found dank guilty of 10 breaches of the sport's anti-doping code.
The AFL's compliance with the World Anti-Doping Agency (WADA) code means Dank is unable to work with any sporting agency around the world that is signed up to the WADA code.
Dank was banned for being the central figure in the Cronulla Sharks' 2011 supplement programme and the Essendon Bombers' 2012 supplements programme.
