MotoGP rookie Jorge Lorenzo, who fractured both ankles during a huge highside at Shanghai on May 2, has been ruled out of the remainder of this weekend's Catalan Grand Prix after sustaining further injuries during a heavy Friday afternoon fall.

The Estoril race winner, who sits third in the world championship standings - 28 points behind team-mate Valentino Rossi - lost control of his M1 at 130km/h through the penultimate right-hand turn after just nine minutes of the afternoon hour.

The Fiat Yamaha rider hit the ground hard on his back before sustaining further blows as he tumbled end-over-end through the gravel.

Lorenzo was initially taken to the Clinica Mobile - where it was at least confirmed that no further damage has been done to his ankles - but further checks at a hospital in Barcelona confirmed new head and hand injuries.

Doctor Xavier Mir of the University Institut Dexeus in Barcelona gave the following statement:

"I can confirm that Lorenzo will not be able to compete this weekend after the tests done here at the Institut Dexeus have confirmed the following injuries:

"1. He suffered head trauma and lost consciousness. We made a neurological examination with a CAT scan and an MRI scan and from this we can confirm that there is no cranial haemotoma or haemorrage. However, he now needs to stay under observation for between 48 and 72 hours to see how this develops.

"2. He sustained an injury to the 4th and 5th finger on the right hand, where he has lost some skin. He also has an abrasion of the extensor tendon. We need to see how this develops but it could be possible that he needs a small skin graft.

"3. Various other bruises and grazes."

Team manager Daniele Romagnoli stated that there was no clear reason as to why Lorenzo lost control and added that - after riding injured for the past three rounds - he hopes Jorge will take the time to recover properly from his latest set back.

"Unfortunately today Jorge suffered another crash and it's clear that the luck is not with him at the moment," said the Italian. "This morning we had a good session and things were going very well, we'd found a good base set up from which to work and we were quite happy with our progress. Then this afternoon started well but sadly after four laps we had another crash when Jorge lost the front at turn 11.

"He was going 130km/h so it was quite a fast crash, but we checked the data and we can't see that he made any particular mistake. We were trying some different tyres and bike setting from the morning and we were feeling quite happy about how things were going so it's a great pity. Luckily he's avoided any further injury to his ankles, but the head injury means that he must undergo a period of rest and not take any further risks.

"We are very disappointed for Jorge, but the important thing now is that he has some rest and takes time to recover properly," he added.

Team director Masahiko Nakajima believes the unusually slippery track conditions - which resulted in seven riders falling on Friday - were to blame for the incident and hopes Lorenzo will be fit to return to action at the British Grand Prix on June 22.

"We are very sorry about this matter and about the fact that Jorge is having to miss his home grand prix," he began. "My feeling is that, after the rain, the track condition today was not normal; it was worse than everyone could have expected. We hope that Jorge recovers quickly and that he will be able to come back in good shape, rested and relaxed, for the next race."