He was great vs France and Madrid, two very physical teams. So... your theory is very selective.
France in a glorified friendly?
Against Real, I don't consider Real as a physical team.
They are more physical than us, but we are historically one of the lightest teams in Europe.
Anyway, these Germans have a marker on De Jong all the time.
And then he is struggling.
As if Germans are aware of him as their main playmaker and are making the biggest pressure on him.
In all 3 matches he was quiet under these circumstances.
But as said,I don't believe that Getafe and La liga teams will be able to cause him similar problems.