Brazil midfielder Kaka said on Sunday he was not fully fit in the 1-0 quarter-final defeat to France at the World Cup and that he should not have played.
Kaka said he had told coach Carlos Alberto Parreira that he was fit to play, even though he was still feeling the effects of a bruised knee which he suffered in the previous game against Ghana in Germany.
"I told professor Parreira that I could play," he said in an interview with Brazilian television. "It was my mistake...I was wrong to have played because when you play with an injury, it limits you.
"In the World Cup, you're amid all that euphoria and you don't know what might happen."
Kaka also criticised Brazil's World Cup preparations in Switzerland, where paying crowds of around 5,000 people watched their training sessions.
"One thing which got in the way was the number of people during the preparations, it affected the concentration of the players and is something which could be improved in the future," he said.