Motta also says Douglas Luiz will have a key role after his summer arrival from Aston Villa.
He said of his striker Vlahovic: "I saw Dusan well, he is training well and I ask him everything. A striker of his level must be capable in both the offensive and defensive phases and must give an important hand to the team.
"We will help him a lot, it will be up to him to work hard. Every day he is very focused on what we ask of him, at work. He must put himself in a position to be able to help his teammates both in terms of achievement and in everything else we need our striker on the pressure, on the depth attack trying to improve every day."
On Luiz, he continued: "He arrived a little later than the others. He is a footballer with great technical quality. It will depend on him, we will support him and we will help, but we will expect a lot from someone like him because he has shown a lot in the English championship. He has everything in hand to have a great season."