MUNICH, June 8 - Costa Rica coach Alexandre Guimaraes says his team are dreaming of upsetting hosts Germany in Friday's World Cup opener in Munich.

"The whole squad are very motivated," he told reporters on Thursday. "There is no reason why we should not play well and who knows what can happen?

"I know we have not had good results in our recent preparation games but I am sure my players will know what to do when the time comes tomorrow. I am sure they will raise their game."

Guimaraes said his squad had a clean bill of health.

"Everyone wants to play in this game because it is so important," he said.

The Brazilian-born coach said it made no difference to Costa Rica that Germany captain and playmaker Michael Ballack would miss the match with a calf injury.

"We have prepared for this game against Germany the team, and not to play against one man," he said.

"It doesn't matter to us if Ballack plays or not."

Guimaraes said Costa Rica were looking to emulate Senegal's shock win over then champions France in the opening match of the 2002 World Cup.

"I don't know if we can repeat what Senegal did to France four years ago," he said.

"For sure that kind of result is always possible and it is a great source of motivation for the team.

"In this game, anything can happen."

The other teams in Group A are Poland and Ecuador.