Brazil head coach Dunga has admitted that he is concerned by the play of forward Kaka, who has already been yellow-carded three times at the World Cup finals.
The Real Madrid ace was booked twice and therefore sent off in the 3-1 group stage win over Ivory Coast and missed the goalless draw with Portugal as a consequence.
He returned for the 3-0 victory over Chile in the round of 16, but was cautioned by referee Howard Webb for a trip on Arturo Vidal and would miss a potential semi-final if he picks up a fourth card in the quarter-final against the Netherlands.
Dunga admitted: "It is a problem - I don't want Kaka to be out suspended.
"It looks as though the technical players are punished and those who commit fouls aren't always.
"This started happening in the group phase and we are going to talk about this with Kaka. It is a concern for him, but we don't want to get bogged down with the issue."