It's up to the Newcastle United boss to manage the 'devil' in the striker, according to the ex-forward.
But only if boss Steve McClaren manages the young Serb correctly.
Indeed, Allon feels the Magpies' summer signing can use his aggression to his and the club's benefit but will need guidance from his Newcastle head coach.
Allon told the Gazette: "Mitrovic has that little bit of the devil in him and for me all good strikers need that. You don’t shake hands before the game - shake hands after the game once you’ve put a few in the back of the net!
"There is a fine line between stepping over the mark or not but that is down to Steve McClaren to manage. But certainly do not lose all the aggression. That can be the difference between having the Eye of the Tiger and not."
What does Mitrovic need to do to justify his price-tag?
After signing only two players, Newcastle United have already spent more than most Premier League teams this summer. But a unique aspect of their Mitrovic move is that the Serb is just 20 years old.
The big-money signing, then, carries a lot of history and responsibility on his shoulders for one so young.
The burden could be shared by another new striker or any of Newcastle's existing forwards should the likes of Papiss Cisse and co remain at the club. Mitrovic, though, will be expected to score goals - and that little bit of 'devil' will hopefully help not hinder the forward in his pursuit of success.