Matts Hummels is injured.
Mats Hummels thigh injury against Portugal means that L?w will likely be forced into changing some cogs of the purring, Germany engine.
The replacement pieces, and there is a range to choose from, will alter the way in which Germany go through the gears against Ghana on Saturday night.
A plague of injuries aside, captain Philipp Lahm will be in midfield for the rest of the tournament. Even ?without? his captain as a right back option, L?w is still left with a plethora of defensive options should Hummels, as expected, not be available.
Shkodran Mustafi may well have come on to replace Hummels in the Portugal game, but it seems unlikely that L?w will start him against Ghana given his lack of international experience.
The same could be said for Freiburg defender Matthias Ginter, a player that appears to have been selected on his ability to play in holding midfield perhaps more than central defence.
Jerome Boateng and Benedikt H?wedes are the two remaining centre back options with more experience. Although they?ve been playing at right and left back respectively, they?ve been acting as additional centre backs in a compressed backline. In any case, L?w will most likely move one of them into the centre.
Whoever he choses, Erik Durm, and perhaps even the less likely, yet versatile, option of Kevin Grosskreutz are the two wingback candidates L?w could turn too.
However, L?w has questioned the persistent use of attacking wingbacks at this tournament. And, given the successful, absorbing nature of the four centre back system that was on show against Portugal, perhaps the inclusion of Mustafi isn?t as unlikely as first considered. Add to that, the more physical nature of Ghana and the inclusion of Mustafi appears even more suited.
Although the rest of the team is in little need of attention after their intimidating display against Ronaldo and Co. the changes made at the back will have a knock-on effect on the players in front of them.
Including Durm would add a width that may lopside L?w?s team, while Mustafi?s nerves could perhaps bring an unwelcome uncertainty (although the presence of Arsenal defender Per Mertesacker, who is set to make his 100th cap, would help Mustafi).
Back in South Africa in 2010, a fine strike from Mesut ?zil was enough to see Germany pick up the three points in a physical encounter against Ghana.
Per Mertesacker said in Thursday?s press conference: ?In the last two tournaments, we couldn?t win our second game after performing superbly in the first.?
The key for Germany is to follow up their statement of intent with action, and whoever L?w picks should be capable of that.