UPDATE 4: Massimo Meregalli, Yamaha team director: "Jorge, after an incredible free practice one, had a crash in the wet in the afternoon and he broke his collarbone.

"This is a real pity as we were coming from two brilliant results and looking for a third. We have to accept this, it is part of our sport.

"We wish him the best to come back as soon as possible and stronger than before."

UPDATE 3: Dr. Xavier Mir: "Jorge has suffered an accident at over 200 kilometres an hour and the obvious injury at this point is a broken left clavicle [collarbone].

"However, as this was a significant accident, we have to take into account that there could also be head, thoracic or abdominal injuries. For now, we have taken him to hospital in Assen where CT scans will be carried out in those three areas to rule out any further injuries.

"It would also be a prudent move to observe him over 12 hours to make sure he can be treated by the appropriate parties when he arrives in Barcelona [for surgery on his collarbone] tomorrow."

UPDATE 2: Jorge Lorenzo 'diagnosed with left collarbone fracture'.

The Spaniard is expected to head back to Barcelona for surgery as soon as Doctors allow, but is clearly ruled out of Saturday's race. Lorenzo previously broke his left collarbone in 2005, then had surgery to remove a plate fitted after that accident at the end of 2009.

"Lorenzo's [fall] was definitely due to a bit of standing water and getting close to the white line. Early in the session there was a lot of standing water, but it cleared as the session progressed" - Michael Laverty, PBM.

UPDATE 1: Lorenzo has a 'suspected left collarbone injury'.

INITIAL REPORT: Reigning MotoGP champion Jorge Lorenzo suffered a huge fall after being kicked from his Yamaha during a soaking wet second free practice at Assen on Thursday.

The rear of Lorenzo's M1 stepped out just as he tipped into a flat out right-hand kink on the back straight, throwing the Spaniard over the handlebars and hard onto the asphalt before sliding across the grass.

Worryingly, Lorenzo was slow to get up and then seen carefully holding his left wrist - which could indicate anything from a shoulder to hand injury - as he headed for a waiting ambulance.

Lorenzo, fastest in the dry morning session at Assen, has won the last two races and closed to within seven points of title leader Dani Pedrosa. The incident - just before the midway mark of afternoon practice - continues a run of Assen bad luck for Lorenzo, who has been taken down on the opening lap at the last two Dutch TTs.

After Assen, two back-to-back events will be held in Germany (July 14) and the USA (July 21st) before the start of the MotoGP summer break.