Chile coach Marcelo Bielsa has dismissed Switzerland boss Ottmar Hitzfeld's claim his side will head into Monday's Group H clash as favourites.
Spain's conquerors and the South Americans meet at the Nelson Mandela Bay Stadium in Port Elizabeth sitting in the top two positions in the group after opening victories, with Chile seeing off Honduras in Nelspruit on Wednesday.
But while the Swiss may have pulled off the shock of the opening round of matches in defeating the European champions, Bielsa is in no danger of under-estimating them tomorrow.
He said: "In this World Cup, if there is something that is not allowed, it is to believe you know who will win.
"Normally, there are no favourites in this competition, and even less so in this than any other World Cup.
"Let's not forget that Spain came to this World Cup as the best team in the world, and deservedly so.
"The Swiss victory was very valuable to them, and you should give credit to Switzerland for that rather than taking it away from Spain."
Switzerland turned in a determined defensive display to frustrate Spain, and then hit them with a Gelson Fernandes goal which proved enough to take all three points.
Bielsa admitted he did not know if Hitzfeld would adopt a similar approach tomorrow, but said his team had to be prepared to deal with whatever is thrown at them.
He said: "Spain had perfect control of the ball, but they had problems attacking because the space was being closed down by Switzerland and their two defensive lines were very close to each other.
"If you are trying to attack and the space if being closed down, you have problems.
"But on the other hand, tomorrow's match might not necessarily be the same. Switzerland has a record of more than just one match.
"They have played other matches with different tactical attitudes, different to how they played against Spain.
"Switzerland played the way they did against Spain to some extent because of the way Spain played against them. Switzerland had to go back and protect themselves."
Victory for the Swiss would secure their passage to the last 16 and could leave Chile needing to get a result against the Spanish in their final game if they are to join them.
But while a draw might prove satisfactory for Hitzfeld's side heading into the last game against Honduras, Bielsa is expecting nothing other than a concerted effort to win the game from Switzerland.
He said: "If you asked the Swiss coach whether he would mind losing or drawing, I don't think he would appreciate your reasoning.
"Whether we win or we draw, it doesn't change anything for the match against Spain.
"We all want to win each and every match. There is always an obligation to try to win and our opponent will be under the same pressure as us.
"But let me put it this way: we are ready, like all the teams, and we are happy to attack and to defend. That's what football is all about."
Real Zaragoza striker Humberto Suazo, who missed the Honduras game through injury, has resumed training and could be involved, although Bielsa admits he remains short of match fitness.
Midfielder Jorge Valdivia picked up a knock against the Central Americans, but is hopeful of making tomorrow's game.