Assen - Spain's three-time MotoGP world champion Jorge Lorenzo will miss this weekend's Dutch Grand Prix and the next race in Germany after a spinal vertebrae fracture in an horrific opening practice crash in Assen on Friday.
Lorenzo slid out at turn seven at the 'Cathedral of Speed' circuit, bouncing into four somersaults as he hit the gravel behind his bike.
Two doctors were quickly at his side and helped him walk gingerly off to the barriers before he sat down and was then taken away to the medical centre by ambulance.
"Sadly @lorenzo99 has been declared unfit for the remainder of the #DutchGP," Honda tweeted.
The 32-year-old is scheduled to spend the next few weeks in a back brace. He will also miss the last MotoGP at Sachensring next weekend before the summer break, making a forecast return at Brno in mid-August.
"Due to the fall I fractured both my T6 and T8 vertebrae," Lorenzo said.
"The injury does not allow me to race here in Assen or at the Sachsenring. Tomorrow (Saturday) morning I will fly to Lugano and do all the possible treatments to get ready to go to Brno."
His Honda team boss Alberto Puig told motorsport.com: "He had a crash also last week in Barcelona, and in that time he was really in pain, exactly in the same area as the place he has the pain today."
Reflecting on the accident he added: "I think he went into the corner faster than normal, and he just crashed -- these things happen. Normally a crash is a human error, mistake, for all of the guys who crash."
Puig said Lorenzo would not be replaced in Assen.
The Spaniard has struggled early in the season after joining Honda from Ducati. He currently lies 15th in the championship standings with 19 points, his best performance an 11th placed finish at the French MotoGP.
Yamaha's Maverick Vinales topped the time sheets in the first two practice sessions on Friday with a best lap of 1min 32.638sec.
He shaded another Yamaha of Fabio Quartaro by 0.180sec with Ducati duo Danilo Petrucci and Andrea Dovizioso in third and fourth, and championship leader Marc Marquez back in seventh at 0.775.
1. Maverick Vinales (ESP/Yamaha) 1min 32.638sec, 2. Fabio Quartararo (FRA/Yamaha-SRT) at 0.180sec, 3. Danilo Petrucci (ITA/Ducati) 0.314, 4. Andrea Dovizioso (ITA/Ducati) 0.585, 5. Alex Rins (ESP/Suzuki) 0.667, 6. Andrea Iannone (ITA/Aprilia) 0.717, 7. Marc Marquez (ESP/Honda) 0.775, 8. Joan Mir (ESP/Suzuki) 0.777, 9. Valentino Rossi (ITA/Yamaha) 0.879, 10.Cal Crutchlow (LCR-Honda) 1.089