Trainer Jim Cerchi jr has been charged with applying a chest rub ointment to the nostrils of a horse before a race at Pakenham.
Petrov was down to run last Thursday but was a late scratching.
Cerchi did not have permission of the stewards to administer any medication to Petrov on race day.
The medication, Chest Rub Ointment (a generic brand comparable to Vicks VapoRub) was allegedly applied to the nostrils of Petrov.
Victoria's Racing Appeals and Disciplinary Board will hear the charge on a date to be fixed.