Kaka is crucial to Brazil's hopes of a sixth World Cup crown, according to team-mate Robinho.
The Real Madrid star is still trying to recover full fitness following a season disrupted by groin and thigh problems and was replaced by Nilmar in the 78th minute of Brazil's opening 2-1 win over North Korea
But Robinho has no doubt that he remains an important figure for Brazil and told globoesporte.com: "When Kaka plays well he can decide any game. He is very important to us. I realise that we can all improve in the coming games. It was only the first one and what happened was fairly normal."
He added: "The Selecao has excellent players and if we have to replace anyone we are reassured by the quality we have."
Brazil are the new 9/2 favourites to win the World Cup after Spain's shock loss to Switzerland.
The Euro 2008 champions have been eased from 7/2 before their 1-0 defeat in Durban to 5/1 by Paddy Power although Spain's overall chances are not too badly damaged with prospects of qualifying from the group still at 1/3.
Brazil are now the market leaders are 9/2 and could now be Spain's second round opponents should Del Bosque's team not win Group H. The Spanish are 9/4 not to make it to the knockout stages.
Paddy Power himself said: "It's the biggest shock of the World Cup so far and punters have taken a right kick in the cojones with that loss today. But there's a long way to go yet and Spain are still in the hunt at least for now."
Although unlikely, Switzerland are now 125/1 to win the World Cup from 200/1 before today's sensational victory.