Argentina's Lionel Messi, seen in the Mexico match, hasn't scored yet in the tournament but is dangerous. ((Ivan Sekretarev/Associated Press))

Germany has identified Lionel Messi is the biggest difference to the Argentina team it beat on penalties four years ago in the World Cup quarter-finals.

Germany midfielder Sami Khedira said that only a collective effort can contain the man he calls "the best player in the world" when the teams meet at the same stage on Saturday in Cape Town.

"You can't shut him down for the entire match and you have to try to contain him with a collective effort," Khedira said.

Although Messi still has to score at the tournament, his attacking play has shone.

Khedira is only too well aware of what the Argentina star is capable of producing, having got a close look when his Stuttgart club faced Messi's Barcelona in the Champions League.

Messi scored twice and set up another goal to lead Barcelona to a 4-0 win over Stuttgart and a 5-1 aggregate score.

Germany striker Miroslav Klose, who is expected to play his 100th international against Argentina, said both teams have been revamped since the stormy quarter-final clash in 2006 when tempers flared and punches were exchanged after the shootout.

"I know they can take revenge for 2006, but it's a different team now. Lionel Messi was on the bench then," Klose said. "We've changed a lot too. Still, when you look at the names, on paper Argentina is simply better.

"But it's what happens on the field that matters. It's how you come out as a team."

Klose has two goals at this tournament and shares fourth place on the all-time World Cup scorers list with Pele at 12.

Klose is the oldest starter in Germany's squad — the country's second-youngest team at a World Cup — but believes it has the right blend to repeat its 2006 quarter-final victory.

"We have a good balance between young and experienced, and we have the quality to beat Argentina," the 32-year-old Bayern Munich striker said.

Thomas Mueller, who leads Germany with three goals and who is growing into a star at age 20, believes Argentina has defensive weakness Germany could exploit.

Argentina defender Martin Demichelis has looked vulnerable and Mueller and Klose are bound to know the weaknesses in their Bayern teammate.

"Argentina's offence is world-class but they have some defensive deficits as seen against Mexico," Mueller said.

Argentina beat Mexico 3-1 in the second round.

"We have to believe in ourselves and we are all pulling together. This determination gives us mental strength to overcome difficulties," he said.

In 2006 at home, Germany knocked out Argentina on penalties after a 1-1 draw through extra time. Klose equalized in the 80th minute to cancel out Roberto Ayala's second-half goal. Germany won when goalkeeper Jens Lehmann stopped shots by Ayala and Esteban Cambiasso.

After the shootout, both sides and officials got involved in a punch-up. Argentina's unused substitute Leandro Cufre was given a red card and FIFA later suspended Germany midfielder Torsten Frings, who missed Germany's semifinal loss to Italy.

Argentina has only one win over Germany at the World Cup and that was when Diego Maradona was still playing in 1986.

Both teams have a long World Cup history, having met five times and twice in the final.

Maradona led Argentina to a 3-2 win in Mexico, while four years later in Italy in 1990, Germany won 1-0 on a penalty. Those were also the last times either team won the World Cup.

Germany won a group match 3-1 in 1958 and the two teams drew 0-0 in another group match in 1966.

Now, Maradona is looking for a win as coach.

Argentina eased past Germany 1-0 in a friendly in March, with Gonzalo Higuain scoring the goal. Higuain also was not in Argentina's squad four years ago.