"The mixture is not ideal at the moment," said Kahn, who captained Germany to their 2002 World Cup final defeat to Brazil. Mueller comically slipped during one orchestrated free-kick which summed up the German's finishing woes. (Agencies)
"There needs to be a better balance between the forwards and the creative players like Mesut Ozil,” he added.
"When you invest too much in attack, looking to find combinations and players in space, you don't always get into good scoring positions,” he said.
Matthaeus, who holds the record of 25 World Cup appearances, said Germany's problems begin in defence as centre-backs Benedikt Howedes and Jerome Boateng have been used mainly as wing backs at the World Cup.
"If you play in an unfamiliar position, you lack rhythm and can't produce a top performance. That was a big problem against Algeria," said the 53-year-old, who won the trophy in
Germany needed late goals from Andre Schurrle and Ozil to edge a 2-1 extra-time win over Algeria in Porto Alegre on Monday and book their date against France at Rio de Janeiro's Maracana stadium.
But Kahn says the poor performance against Algeria could act as a catalyst with Germany chasing a fourth World Cup title.
"Sometimes such a negative match in the last 16 can have a healing effect for the next matches," said the 45-year-old.
"I cannot remember a World Cup where the Germans didn't have at least one really bad game,” he added.
The Germans are making no excuses for grinding out a win over the North Africans by adopting a 'winning ugly' mentality.
Only an outstanding performance from goalkeeper Manuel Neuer kept Algeria out before replacement Abdelmoumene Djabou netted a consolation goal just before the whistle.
Failed to impress
Germany have failed to impress at Brazil 2014 since their opening 4-0 drubbing of Portugal with both their public and media increasingly eager to see good football.
A nervy 2-2 draw with Ghana in Fortaleza was followed by a drab 1-0 win over the USA in torrential rain in Recife in their other group matches.
Joachim Loew's Germany dazzled at the 2010 World Cup, routing England and Argentina 4-1 and 4-0 respectively but four years on they make no excuses for grinding out results.
Centre-back Per Mertesacker reacted angrily when a reporter asked him why the Germans were so "cumbersome and vulnerable" against Algeria.
"I couldn't care less, we're in the last eight and that's all that counts," fumed the Arsenal defender.
"Do you think that because we're in the last 16 now that we should be some sort of entertaining circus act or something?” a furious Mertesacker questioned.
Mertesacker was incredulous when directly asked why Germany are not playing the impressive football of 2010.
"What do you want? Do you want a successful World Cup or do you want us to get knocked-out again having played nice football?" he demanded.
"I don't understand these questions. We have reached the next round, we're super happy, we gave everything and now we're preparing for France,” he added.
Loew has admitted his side must improve for their French date with their finishing of particular concern.
Germany enjoyed 68 percent possession and had 28 goal shots compared to the Algerians ten as forwards Thomas Mueller and Mario Goetze struggled.
"The mixture is not ideal at the moment," said Kahn, who captained Germany to their 2002 World Cup final defeat to Brazil.
Mueller comically slipped during one orchestrated free-kick which summed up the German's finishing woes.