Germany has been working on ways to isolate tall Serbia striker Nikola Zigic and prevent him from distributing the ball to teammates in their upcoming Group D match.
The 2.03-meter (6-foot-8) Zigic uses his height to head long balls into the path of teammates.
This aspect of Serbia's game has been closely scrutinized by the Germans ahead of Friday's game, according to Germany midfielder Sami Khedira.
``We will have to win those balls laid on by Zigic,'' Khedira said.
Assistant coach Hansi Flick said Germany's central defender Per Mertesacker was tall enough to match up against Zigic, who has signed for Birmingham City for the next English Premier League season.
``Our central defenders won all high balls against Australia, so we are in good shape,'' Flick said.
Mertesacker is 1.98 meters (6-foot-5) tall.
While Germany impressed in its 4-0 opening win against Australia, Serbia lost 1-0 Ghana and needs at least a draw against Germany to have a chance of advancing.
``It's their last chance to stay in the tournament and we'll have to be very careful and concentrated. But we are confident,'' Flick said.
``Australia was no measuring stick and Serbia is a very good team, with players in top clubs in Europe. We'll have to improve what we did well against Australia and we are confident we can do it.''
Defender Holger Badstuber predicted the Serbs will be dangerous now that their backs are to the wall.
``We know the players they have, some are from the Bundesliga. We got off to a good start but this is going to be a different number (than Australia),'' Badstuber said.
Khedira said Germany would have to get into the game quickly, as it did against Australia.
``We'll really have to watch out, they will be motivated and hot,'' said Khedira, who has taken up some of the duties of the injured captain Michael Ballack and usually carries the ball forward.
Germany coach Joachim Loew also has warned his team against complacency after a strong start to the tournament.
``They have been affected by the loss to Ghana. But they a very strong team. They can dominate and dictate a match and they have to win, which makes them such a dangerous opponent,'' Loew said.
Loew's young team ensure a place in the round of 16 if it beats Serbia.
Germany expects to have midfielder Bastian Schweinsteiger in the lineup although he has been suffering from a cold and has missed two training sessions.
``We are not worried, he should be fine to train tomorrow in Port Elizabeth,'' Flick said.
Germany lost only once to the former Yugoslavia in a World Cup, in 1962 in Chile. But it was knocked out by one of the successor states, Croatia, in the quarterfinals in 1998.
