Hopkins out for six to eight weeks.

John Hopkins, who sustained leg injuries during a high-speed Assen qualifying accident, will definitely miss the next two races - and possibly Brno on August 17.

Hopkins fell at 230km/h towards the end of qualifying for the Dutch TT, after losing the front of his Ninja ZX-RR at Ramshoek corner, the ultra-fast left-hander just before the final chicane. The Kawasaki pilot slid across the track and through the gravel trap before colliding feet first with the tyre wall on the outside of the turn.

X-rays of his injured left leg at the circuit medical centre revealed that Hopkins had sustained a fracture to the bottom of his tibia and that he had reopened a previous fracture, the result of a crash earlier in his racing career. The x-rays also showed a fracture to the lateral malleolus, which is one of the bones at the top of the ankle.

Hopkins had a further medical examination by Dr. Art Ting on his return to America last week. In addition to confirming the previously diagnosed fractures, a bone scan of the injured left leg also revealed a tibial plateau fracture just below the knee, and damage to the meniscus (cartilage), which was causing Hopkins' knee joint to lock.

Hopkins underwent successful surgery in Los Angeles on Monday to reset the bones in his ankle. During the operation, the meniscus in his left knee was also repaired and attached to the bone using keyhole surgery techniques.

As a result of the surgery Hopkins will not be able to bear any weight on his damaged left leg for three weeks, after which he will undergo extensive rehabilitation therapy, with a full recovery from his injuries expected to take between six to eight weeks in total.

The current goal is for Hopkins to make his return to racing at the Czech Republic Grand Prix, in six weeks.

"I am sorry for John, as I know he was looking forward to racing in front of his home crowd at Laguna Seca, where he always enjoys a lot of support," said Kawasaki competition manager Michael Bartholemy. "But it's just not possible; he has had surgery to fix the injuries he sustained at Assen, and now he needs sufficient recovery time to ensure that he's fully fit before he makes his racing return.

"Obviously we are hoping that this return will come at the Czech Republic Grand Prix, but we will be monitoring John's recovery very closely and we have no intention of putting him back on the bike before he's ready. If this means he doesn't race at Brno, then that's how it will be, because we don't want to risk making things worse by allowing him to return before he is fully recovered," he declared.

Bartholemy added that, whilst there will be no replacement rider at this weekend's Sachsenring event, an announcement is imminent regarding a substitute rider for the US Grand Prix.

"Now we know the full extent of John's injuries we are looking at the possibility of running a replacement rider at Laguna Seca," he confirmed. "We will make a further announcement about this ahead of this weekend's German Grand Prix."

Bartholemy has previously revealed that Kawasaki's AMA riders Chaz Davies, Roger Lee Hayden and Jamie Hacking top his list of candidates to steer the second ZX-RR alongside Anthony West at Laguna Seca.

Kawasaki had been interested in placing troubled Ducati rider Marco Melandri on Hopper's vacant ZX-RR, but the Italian factory stated that Melandri will remain on a Desmosedici until at least Laguna Seca.