The Arsenal defender has little doubt Jaochim Low's men will bag three points on Tuesday and has insisted his side must defend as a team.
A win will confirm Germany's qualification for next year's tournament in Brazil if second-placed Sweden fails to beat Kazakhstan on Tuesday and Mertesacker is confident the team will record a positive result.
"We have been warned to expect difficult conditions. We have to adapt to the pitch as soon as possible," Mertesacker told reporters.
"But with the 3-0 win over Austria on Friday behind us, we are confident we can take the next step towards the World Cup."
The Arsenal man then went on to say that it's crucial for Germany that it defends as a team if it is to be successful and added that the reserves must always be ready whenever called upon.
"We have to be careful to defend as a team. Even if you don't play, you have to support the team and you never know when you'll be needed or what the next team selection will be.
"We have plenty of good individual players, but what is important is that the team evolves."