Parling was injured during training at England's Pennyhill Park base.
"Geoff Parling sustained a mild concussion during a contact session this afternoon and will undergo the recommended graduated return to play protocol," Lancaster said in a statement.
"As such, he will be unavailable for Saturday's game but will stay in camp with a view to returning to training next week."
Lancaster will announce his team to play the Wallabies on Thursday.
England also play Argentina and New Zealand in November.