Germany take on South Africa, who will host the competition, in a friendly next Saturday, before facing Azerbaijan in a Group 4 qualifier on 9 September, but Loew says his team is weaker than in the past
Since then, unconvincing wins over Wales and Azerbaijan, plus a 1-1 draw with China has done little to boost Loew's confidence, with his side facing Russia in Moscow in October where victory would take his team to South Africa 2010.
Germany top Group 4 with a four-point lead over Russia, who have a game in hand and Loew insists his aim is to win the group to claim a guaranteed place in South Africa.
But Loew acknowledges that it has been hard to keep his side at the same level they reached last summer on their way to the UEFA Euro 2008 final.
"It is not easy to stay at the same level for several years, but I am sure we will reach those levels again and our supporters enthusiasm will return," said Loew, who took over as Germany coach in July 2006.
Fifa World Cup 2010 the cup 2010 fifa 2010
"We have not always exploited our potential in recent games like I had imagined we would," Loew said, with his side fourth in the FIFA/Coca-Cola World Ranking behind Brazil, Spain and the Netherlands.
"We have not always been convincing and we must find the way to recapture our form. This year we have not dominated our opponents; that has been one of our weak points.
"We must work to make sure the opposition is constantly under pressure and are forced into errors," Loew said.
"We must work to make sure the opposition is constantly under pressure and are forced into errors," Loew said.
Since losing the UEFA Euro 2008 final to Spain in June of last year, Germany suffered rare consecutive home defeats over the winter when England won 2-1 last November in Berlin, followed by a shock 1-0 defeat to Norway in February.
Since then, unconvincing wins over Wales and Azerbaijan, plus a 1-1 draw with China has done little to boost Loew's confidence, with his side facing Russia in Moscow in October where victory would take his team to South Africa 2010.
Germany top Group 4 with a four-point lead over Russia, who have a game in hand and Loew insists his aim is to win the group to claim a guaranteed place in South Africa.
But Loew acknowledges that it has been hard to keep his side at the same level they reached last summer on their way to the UEFA Euro 2008 final.
"It is not easy to stay at the same level for several years, but I am sure we will reach those levels again and our supporters enthusiasm will return," said Loew, who took over as Germany coach in July 2006.
Fifa World Cup 2010 the cup 2010 fifa 2010