Mertesacker, who has 62 international caps to his name, said: "Tim Cahill has enormous experience and has grown tremendously in England, he is one of Australia's most dangerous players and will be their midfield maestro. But if we can mark him tightly, it will make it hard for him to play a role."
Mertesacker was paired with new Schalke-signing Christoph Metzelder at the last FIFA World Cup™ in Germany, and the duo proved to be, statistically, the best centre-back pairing of the tournament. This time he will line up alongside Hertha Berlin captain Arne Friedrich, but the Werder Bremen star revealed the Germany defence plans on being just as efficient in containing Cahill.
"We will try and nip his attacks in the bud, and maybe even double mark him," he said. "But he is still dangerous and can create chances in front of goal, so it will be hard to contain him."
Mertesacker has some experience of coping with Australian forward Joshua Kennedy, from his time in the Bundesliga with Wolfsburg and Cologne, and the German is ready should the pair clash on Sunday. "He is a very robust player, very good in the air and uses his body to get some advantage, so the aerial battles will be challenging," he said.
Germany have a 100 percent record against Australia from their two previous meetings, but the Socceroos gave the hosts a mighty scare on their last meeting in 2005 before going down 4-3 in a Confederations Cup clash in Frankfurt. Mertesacker hopes his side can avoid any such scares this time around. "We would like to hit the ground running here with a victory and as for conceding three goals, well, let's just say the curious thing was I scored that day," Mertesacker smiled.
Joachim Loew's side will increase their focus on Australia in training this week and, Mertesacker admitted, they are eager for the World Cup to begin. "We haven't dealt with the issues around Australia so intensely yet, that will come in the next few days," he said. "The next few training sessions will be decisive to get organised come the Australia game. We are all really dying to get cracking after all this time waiting."
With Serbia and Ghana also awaiting Germany in Group D, a defeat in the opening game would be a serious set-back. "We are concentrating on the first group game, because we know a lot can happen in the group stages, especially early on," said Mertesacker. "We need to get as many points as possible, as soon as possible. I don't want to be negative about it, but it would be a very bad start for us to lose the opening game to Australia."