Lahm and keeper Manuel Neuer are recovering from injuries and have yet to start training, while playmaker Schweinsteiger and defender Marcel Schmelzer train alone at their northern Italy training camp.
Holding midfielder Sami Khedira only recently returned to action after six months out injured and although he played for an hour for Real Madrid in Saturday's Champions League final he was replaced after an hour after failing to make much of an impact.
"(When you) see reports you would think that we are in a hospital here but that is not the case," he told reporters in his first news conference since the team's arrival in the Italian Alps for a 10-day camp last week.
"We will travel to Brazil with a competitive and good team. The players are working very well and as it stands now I am very satisfied. Some are still injured and cannot fully train with the team but they are all training individually and I am very confident that it will work out."
Germany, drawn with Ghana, Portugal and the United States in Group G, are eager to end an 18-year title drought and Loew said all would be fit in time for the tournament starting in Brazil next month.
"Philipp will start running tomorrow and then we have to see every day. We should not force it," he said, adding that Neuer would continue receiving treatment for an injured shoulder.
He said players like Lahm, Schweinsteiger and Neuer would not be affected too much if they missed a few days of training.
"We assume that all of them will be fully fit within days," said the 54-year-old, sipping an espresso.
"That is what they are working on. According to our medical department these are all short-term injury and I see no problem."
With Lahm expected to be fit well before the tournament starts, Loew will delay his decision on where to deploy the right back, with his captain eager to move into a permanent role in midfield.
"We will decide during the preparation where he will play," said Loew, whose team take on Cameroon and Armenia in World Cup warm-up games on June 1 and June 6.
"It also depends on other players. It is still a bit early. We have to see what happens with Khedira and Schweinsteiger. We will take a decision after those friendlies."
- Sports & Recreation
- Sami Khedira
- Manuel Neuer
- Real Madrid
- Marcel Schmelzer