The 22-year-old has failed to pick up a point since it was announced that he would be leaving the team for McLaren next season.
"He knows how important it is for us to score at the remaining races," said Kaltenborn. "Maybe it's his inexperience that sometimes pushes him to do more than he should.
"That's nothing we can reproach him for because he's trying his best to do something good for the team before he leaves. But we definitely will talk to him, although I think he is mature enough to know what is at stake."