Lacking fitness: Kaka was not fit enough to play in a World Cup finals, according to Brazil's team doctor

Brazil fell in the quarter-finals for the second successive World Cup after suffering a surprise 2-1 defeat to Holland,and Kaka struggled to find his best form during the tournament.

"Maybe in other situations Kaka would not have played in the World Cup, but he really wanted to be there," Runco said.

Kaka came into the tournament off the back of a disappointing first season with Real Madrid, which saw him miss more than six weeks due to a recurrent thigh injury.

Kaka was under the spotlight after his £54-million transfer from AC Milan and failed hit the heights which saw him crowned European footballer of the year in 2007.

"I suffered a lot since I got injured," Kaka said.

Read Madrid's supporters were quick to turn on their new signing and whistles and jeers were aimed in his direction during the Spanish side's defeat to Lyon in the last 16 of the Champions League in March.

"They did it [whistle] in Sao Paulo, Brazil, with Milan... it happens to all players. The fans are very emotional," Kaka said.

Kaka failed to score in the World Cup and was also red-carded in the group stage win over Ivory Coast.