With four minutes remaining of the second free practice session on a wet Hockenheim circuit as rain had dominated the 90 minutes, Schumacher suddenly lost control of his car and ploughed into a tyre barrier.
With the front and rear ends of the car damaged given the way he spun around upon impact, his mechanics face a long night carrying out repairs ahead of Saturday's qualifying session.
It was a rookie mistake from the seven-times world champion as he conceded: "The way I ended the second session was obviously not part of the plan.
"I'm sorry my mistake has given my guys even more work to do this evening.
"I simply slid off track because I lost a little concentration. We were talking on the radio and I was altering some settings at the same time."
On-board footage, however, undermines Schumacher as it shows him with both hands on the steering wheel at all times leading up to his crash.
As for team-mate Nico Rosberg, his compatriot faces a five-place grid penalty for a gearbox change, but the 27-year-old remains upbeat.
Rosberg said: "Unfortunately we have to change my gearbox as a precaution after discovering an issue after Silverstone (at the British Grand Prix).
"The penalty is a shame for our home race, but I will push hard to gain a good result. As we have seen this season, a lot can happen in the race."