Spain coach Julen Lopetegui says striker Diego Costa must be loved "the way he is" but admitted the player's conduct can damage his reputation.
Costa, 28, was dropped by former Spain boss Vicente del Bosque after a series of altercations with opposing players on club duty with Chelsea and failed to make the squad for Euro 2016.
But Lopetegui has since welcomed him back into the fold and he scored his first international goals for two years last month in an 8-0 thrashing of Liechtenstein.
"Players keep developing right until they retire," Lopetegui told El Larguero. "You can change in a positive way if you make the right decisions.
"Diego has a certain character. He is a fighter. But sometimes his reactions hurt his reputation.
"He will be able to iron out these things as he develops. He is aware of it and so are we. These things can cost him. It could be hurtful to him.
"But we must love Diego the way he is and try to understand him. Any small advantage can make the difference in a tight game."
Costa started and played 67 minutes as Spain drew 1-1 in Italy on Thursday in a World Cup qualifier. They travel to Albania on Sunday for their next tie.