Udinese coach Giovanni Galeone believes midfielder Sulley Muntari must toughen up if he wants to play for a bigger club.
The Ghana international is wanted by Middlesbrough and Portsmouth this month and Galeone said: "If Muntari leaves us, I will cry.
"The lad has only one defect, he's too emotional and when things go wrong for him he reacts poorly. He must understand he needs to be stronger if he wants to be regarded as a top European player and such behaviour will not be tolerated at bigger clubs.
"He must mature. He needs a coach who can guide him and understands his character."