Both Germany and the US are through with a draw so neither is going to take any risks I think. There's simply no reason to so if the US has a solid defense Germany probably won't press too hard.
Also Löw and Klinsmann are good friends, for what that is worth.
Also, while no one is "afraid" of Portugal per se, there's no reason to make it possible for them to make it to the next stage and then have to face the prospect of C Ronaldo taking over a game. Not many players can actually do that, and he's probably not completely fit, but still...chancing Clint Dempsy taking over a game sounds a lot more palatable.
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