Paulo Sergio has called on Douglas Costa to learn from Neymar after an impressive start to life at Bayern Munich.
The Brazil international has enjoyed a stunning debut season in the Bundesliga after moving from Ukraine's Shakhtar Donetsk in the summer transfer window.
That form has made him a key part of Dunga's Brazil team, and his compatriot Paulo Sergio praised his mental strength.
"I am surprised [by Costa's impact]," the former Bayern forward told Goal. "When he was at Shakthar Donetsk in Ukraine it was not so easy to follow him. But he has the qualities you need nowadays to be succesful: dynamic and skills.
"If you combine that with the right mentality you will establish yourself in Germany. But you could not expect him to adapt as fast as he did.
"The transfer was a surprise. I knew he had many things to offer. We met in Munich ahead of his presentation. It was important to me to give him a little advice. I told him to show what he can do in every training [session]. And with such a club you always have to stick to your style."
When asked whether Costa could deliver success with the Brazil national team, however, the 1994 World Cup winner was less certain.
"We'll have to see," he said. "In the past he did not meet the expectations. After his performances for Bayern there are many people who think he fits perfectly with Neymar.
"What he can learn from Neymar is the killer instinct. That's what he is lacking."