Dunga took charge of Porto Alegre club Internacional on Wednesday, his first coaching job since leading Brazil at the 2010 World Cup in South Africa.
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"To work with me, you have to be committed, you have to have the will to win," he told reporters after being presented by the club with which he started and ended his playing career
"I never left Inter, I was always here as a fan. Inter opened their doors to me when I was 14 years old and now I'm ready to pay them back."
Under his leadership Brazil developed a physical, counter-attacking-based game which was unpopular with many fans and their World Cup campaign ended with a 2-1 quarter-final defeat by the Netherlands.
Dunga also alienated the media with what they called his siege mentality.
"Inter have a strong tradition," he said. "Inter fans will accept everything, except when players don't give everything for 90 minutes."
"The worst defeat of all is when you get home and think you could have done better. Everybody has to be committed."
As a player, Dunga was a feisty, defensive midfielder with a spiky haircut and almost permanent snarl who played in three World Cups. He captained the side who won the tournament in 1994 and led them to second place four years later.
His club career took him to Corinthians, Vasco da Gama and Santos in his homeland, Pisa, Fiorentina and Pescara in Italy, VfB Stuttgart in Germany and Japan's Jubilo Iwata.
Inter won the Club World Cup in 2006, beating Barcelona in the final, and are twice South American champions and three-time Brazilian championship winners.
They finished 10th in this year's Brazilian championship. Dunga replaced Fernandao, a player in the 2006 team who was fired as coach in November.
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