Romero, who has conceded two goals in four wins, faces one of the higher scoring attacks at the finals when they meet in a mouth-watering clash in Cape Town.
The giant 23-year-old knows he must also be prepared for a penalty shootout which is how Germany eliminated Argentina in Berlin at the same stage of the 2006 finals.
"We have been studying the penalties of all players since the World Cup started because we know that at any moment we might have to face one and you need to know about the taker," the 1.92-metre tall Romero said on Tuesday.
In the 2006 quarter-final shootout, Germany goalkeeper Jens Lehmann benefitted from a crib sheet he had on him with details of Argentina's likely penalty takers. Germany won it 4-2.
"It was a piece of cunning by them for the goalkeeper to have a little paper tucked away to know about the players who were going to shoot," Romero told a news conference.
"I think that with the work we're doing we're ready for any time in the match, during the 90 minutes or in penalties," he said after Monday's practice at Argentina's University of Pretoria base.
'GREAT FORWARDS'
Romero said Germany, who have scored nine goals to Argentina's 10 in four matches, have "great forwards and great fighters when they don't have the ball.
"(Lukas) Podolski has a great shot from distance, he always sets up his left foot to shoot, (Miroslav) Klose chases every ball, he doesn't give any up for lost, (Mesut) Ozil plays very well, he's technical, they have tall people who go to all the corners and free kicks."
Romero believes he is playing behind a very strong defence but he needed left back Gabriel Heinze's two clearances off the line to avoid conceding more goals against the Mexicans in their 3-1 win on Sunday.
"Only two or three balls reach me per match, not more than that, and I think that means I have a good defence," said the keeper with the long ponytail who has won the World Youth Cup and Olympic soccer titles with Argentina.
Romero has been criticised for punching the ball away at times rather than trying to catch it.
"In a match you can't run any risks," he said.
"If you have to parry, you parry it, if you have to catch it you catch it and I think that's how a goalkeeper gives his team mates confidence," he added.