Friedrich, who is out of contract at Hertha Berlin and set to leave following their relegation from the Bundesliga, and Werder Bremen's Mertesacker will be Germany boss Joachim Low's first choices at the back in South Africa.

Friedrich and Mertesacker are experienced campaigners and the 31-year-old believes both men will have to display leadership qualities if the Germans are to advance from Group D, which also contains Australia, Ghana and Serbia.

"I do not think Per is my boss," said Friedrich, who has won 72 caps for his country.

"We both have to take on a lot of responsibility for the organisation of the team."

Friedrich could offer no update on his club future, adding: "We are holding talks but my advisor is looking after this.

"But as there is still no definite decision, I would rather not say anything more about this."