Just one match into the Qatar World Cup, Germany face what amounts to a must-win clash against Spain on tonight, a team they have not beaten in a competitive fixture since 1988.

Before Germany were stunned 2-1 by Japan in their opening match, the team faced heavy criticism for backtracking on a promise to wear a rainbow "OneLove" armband in support of diversity and human rights.

But after Japan scored two late goals to beat Hansi Flick's team, the Germans were hammered by some observers for losing focus on the football when they should be concentrating on avoiding a second successive group stage exit in a World Cup.

On Friday, Chelsea striker Kai Havertz said the players were holding onto their beliefs but knew the challenge ahead, especially against a Spain team that steamrollered Costa Rica 7-0 in their opening game.

"Everyone knows our point of view and how we think," Havertz said in a pre-match press conference.

"Really, our focus is 100 percent on football, nothing else. We just said what we think, what our point of view is, everyone knows that, and now it is about playing football."

With supermarket chain Rewe pulling their sponsorship and with TV ratings for the Japan game the lowest in Germany for a World Cup in more than 30 years, Havertz recognised that the challenges were not just on the field, saying: "I know not everyone is behind us."

Speaking with Germany TV network ARD on Friday, Bierhoff said losing "our first final" in Qatar would have widespread ramifications for the sport.

"What does it mean for German football? For the further development?" Bierhoff asked.

"And if you go a little deeper: (what does it mean) for the investment we have to make to stay competitive (and) to have new players in eight or ten years?"