Seven German players were reportedly suffering from mild flu syptoms, says German coach Joachim Loew in a German radio interview.

It would be a crucial factor into their upcoming quarterfinals game against France on Friday.

However, he did not identify the names of the players.

"Seven players have somehow come down with slight cases of the flu," Coach Loew told Germany's ARD radio. He said that most had "throat aches" but he did not disclose their names.

"As a result, it's too early to make any final decisions about the line-up," Loew added.

Cristoph Kramer, reserve midefielder of the team, was reportedly having chills since Wednesday. He was also unable to attend the training session. This information was revealed by assistant coach Andreas Koepke.

Koepke said that the other players were all fit and ready for a trip to Rio de Janeiro for the quarterfinals match.

Nevertheless, the coach said that the difference of climate zones in Brazil for their four matches so far has affected the team greatly. They experienced tropical heat, heavy downpour of rain, and then a cold day in Porto Alegre. The air-conditioning could have contributed, too.

"I hope they're all doing well now," Loew said.

The coach also said, "It's not all that bad at the moment. I don't want to dramatise it."

But Loew said that Hummels illness had actually worsened.

"Mats Hummels suffered a negative setback on the second day," Loew said.

The German coach had to put his captain, Philipp Lahm in the midfield, instead at the usual right back. The latter position has been his great spot for years.

In their last match, Germany has managed to defeat first timers Algeria and advance to the quarterfinals in a 2-1 win after some extra time. Germany has been so far, a competitive team in the World Cup, after they too, had finished first in the Group G over America, Portugal and Ghana.