IMO Popp is the biggest favorite of all three German players mentioned here.
He should be able to overcome Carlsen. Come on, Popp!!! please no choking like against Clément in Halle
You can do it!
Schüttler vs Spadea... well, I will call this a "solvable task", but I'm not so sure about Spadea as he I always see him as a tricky opponent.
But I see a good chance for Rainer to do well here.
And Mayer vs Ferreira. Well, Mayer did very well so far, but let's not forget it's his first time he went this far and you never know how young players deal with that as a 3rd round Grand Slam match is no "routine" for him. Veteran Ferreira plays a Grand Slam for the 56th time in his career and is no stranger to that.
Of course, I see chances for Mayer, but Coria and Ferreira are two different styles and Escudé killed Mayer in Paris with his strong serve and volley game so I would be careful with predictions here as Ferreira has a similiar game and that could be difficult.
I hope for Mayer to play a good match and not have a mental letdown after his two good matches. If it's not enough at the end, he at least tried his best.