Mercedes team principal Toto Wolff said Ferrari "have an illness" following a terrible qualifying session at Hockenheim on Saturday in which both drivers suffered mechanical failures.
Sebastian Vettel will start his home grand prix from the back of the grid after a turbo problem forced him into a first Q1 exit since the Malaysian Grand Prix of 2017.
Charles Leclerc looked in good form until a fuel issue left him unable to set a time in Q3, meaning he will line up in 10th place on Sunday.
A galling day for Ferrari, who had set the pace in Friday's practice sessions, was compounded when Mercedes' Lewis Hamilton claimed his fourth pole position of the season.
Wolff said to Sky Sports: "It's a shame for Ferrari and a shame for Sebastian at his home grand prix as we need him here for the crowd. You can see it's a bit subdued at the moment. Ferrari really have an illness in there at the moment which they need to cure.
"We need them for a strong championship, but for us I'm happy. The session started awfully, and we didn't understand why we were lacking pace, but slowly it came towards us."Published 27 Jul 2019, 21:00 IST