Daily Bild also reported that Manuel Neuer would be the starting goalkeeper for the team when it kicks off its campaign for a fourth title next month.
The paper reported that coach Jogi Löw told Lahm yesterday that the 26-year-old defender would lead the team and that officials would announce the decision before Germany's friendly against Hungary on Saturday.
Quizzed at Munich airport yesterday, Lahm did not discuss the role of captain but said his job in the team was “to move forward and to reinforce the belief and the confidence that we will have a very successful World Cup.”
Lahm, considered one of the best full-backs in the world, scored Germany's opening goal in the 2006 World Cup and has been a major presence in the lead-up to the 2010 competition. He was the only player to play all 90 minutes in all ten matches in the qualifying campaign.
He has also stood in for Ballack in several recent friendly games.
Asked whether Germany could win, Lahm said: “Yes, because we are a tournament team and always have the quality to will the title. We have young players of quality and we will play together as a team.”
With an average age of 25.28, Germany will field its youngest World Cup team since 1934.
Ballack, 33, who is also a Chelsea midfielder, suffered torn ankle ligaments in the recent FA Cup final win over Portsmouth after a heavy tackle from Kevin-Prince Boateng. The German national team doctor then ruled that Ballack, who was a crucial part of their bid to win the World Cup for a fourth time, would not recover in time for the tournament.
Germany will begin its World Cup campaign with a match against Australia on June 13.