The 20-year-old rookie sensation, currently holding the joint world championship lead after three podiums - including one win - from his first three MotoGP races, was propelled spectacularly into the air when his rear tyre lost traction as he switched from right to left, midway through the morning session.

After an initial examination at the circuit clinic Lorenzo was taken to the nearby Huashan hospital for an MRI scan and further detailed diagnosis, before returning to the track and spending the remainder of the day resting at the Clinica Mobile.

It is not yet known if Lorenzo will return to action on Saturday and defend his 100% pole position record, but Dr Claudio Costa of the Clinica Mobile thinks it will be 'very difficult'.

"Detailed examination has revealed that Jorge has re-fractured the top of the malleolo bone in the middle of the left ankle," said Dr Costa. "Furthermore, the MRI scan showed that there are severe impact oedemas to the right heel, the astragalo bone and the tibia, but fortunately no signs of further fractures. The diagnosis shows the violence of the trauma he suffered to both his feet in the crash and Jorge now faces a very difficult task to participate in tomorrow's qualifying and Sunday's race."

Lorenzo's crew chief Ramon Forcada also admits it will be 'very hard' for Lorenzo, who had recently undergone surgery to help cure arm pump problems, to ride on Saturday.

"It's a great pity this has happened, right at the start of Jorge's weekend; we were focused on his arm following his recent operation and we were quite confident that he could ride as usual," said Lorenzo's crew chief Ramon Forcada. "It was a very bad crash and it is not clear yet what happened because we lost all the data when the equipment was damaged at the time.

"As far as we can see from the TV, he lost grip on the rear. I do not know if Jorge will be able to ride tomorrow, but in any case we have lost two sessions and we will have to work today in order to prepare the bike with an ideal set-up for tomorrow. It will be hard, very hard, as tough as Jorge is!" Forcada admitted.