The former defender says the Serbian forward must start to show his physicality in a positive manner.
The striker was signed from Anderlecht for a reported £13m in the summer, according to the BBC, as new manager Steve McClaren spent money to overhaul his squad and his forward line.
He has had an eventful start to his spell at St James' Park, with ill discipline looking like it will be a problem they will have to resolve in order to get the best out of the forward.
He scored his first goal in the 6-1 defeat to Manchester City last time out, though, and Howey has predicted that he will prove his worth on Tyneside.
"I think he will be a hit... if he knuckles down," he told Sky Sports.
“You saw in the first half against Manchester City that he caused them all sort of problems. If they get the ball in the box enough times, he will cause problems. Unfortunately, this season the ball has not been coming into the box that much when he has played."
On the subject of his ill discipline, Howey believes that Mitrovic needs to show his passion in a different way, but feels his physicality is a bonus to the side.
The Serbian started his Premier League career by picking up two yellow cards in his first two games, before going one step further and getting sent off against Arsenal early on.
Howey, though, says that physical side of his nature could be a positive to McClaren’s side if he uses it in the right way.
"You want that passion, that desire, but it has to be done in the right way," he added.