Lorenzo is to undergo further surgery just two weeks after eight screws and a plate were inserted to repair the collarbone he broke during practice for the Dutch round in Assen.
Early in Friday second session at the Sachsenring, Lorenzo flipped over the front of his factory Yamaha, landing on his left shoulder.
Following a series of checks and an x-ray at the circuit medical centre, it has been discovered Lorenzo has bent the titanium plate, so requiring another operation.
Unlike a fortnight ago when Lorenzo astonishingly finished fifth in Assen less than 48 hours after surgery in Barcelona, on this occasion there will be no miracle return.
"I have decided to go home and recover after today's [Friday] crash at the Sachsenring," said the 26-year-old from Majorca.
"I prefer to focus on surgery to fix the plate that was unfortunately bent during the crash. I will try to recover and be back as soon as possible."
It means Lorenzo is already a doubt for next weekend's United States GP at Laguna Seca, and opens the door for championship leader Dani Pedrosa to strengthen his grip at the top of the standings as he only has a nine-point lead.
Prior to his accident Lorenzo has looked strong, finishing quickest at the end of the first practice session with a time that proved to be the second fastest overall come the conclusion to the day.
Top of the timesheet was home hero Stefan Bradl on his LCR Honda, the German setting a time of one minute 22.030secs, just 0.017secs clear of Lorenzo.
Pedrosa was third on his factory Honda ahead of team-mate Marc Marquez, followed by Lorenzo's team-mate in Valentino Rossi, who won his first race for almost three years in Assen.
As for Britain's Cal Crutchlow, fourth in the championship standings and 49 points adrift of Pedrosa, the two sessions proved to be painful affairs.
Crutchlow was one of a trio of riders who fell heavily at turn 11 in first practice, Andrea Dovizioso and Andrea Iannone the others, with the latter's Ducati ending up in two parts.
Come FP2, the same corner again caught out the 27-year-old around 15 minutes in, forcing him to sit out the remainder of the session due to scrapes and burns to his left hand.
Crutchlow was sixth quickest in FP1, 0.422secs adrift of Lorenzo, but due to his accidents in FP2 finished 19th, almost two seconds down on Bradl.
Tech 3 Yamaha team-mate Bradley Smith was a second off the pace in 11th.
In Moto2, Britain's championship leader Scott Redding was quickest with a time of 1:25.152, faster than the track's race lap record for the series.