Kawasaki has confirmed that John Hopkins will not be fit enough to compete in the next two MotoGP rounds, but have added that Marco Melandri will not be replacing him.

Hopkins is to go under the knife for the leg injuries he sustained in his high-speed crash at the Assen TT, surgery that will therefore rule him out of the coming rounds at the Sachsenring and his home event at Laguna Seca.

"He needs to have an operation, according to Dr Ting, because the tibia is still a little bit dislocated and he would like to correct this," Kawasaki Racing competition manager Michael Bartholemy told the official MotoGP website.

"Also he would like to perform some surgery on the knee because there was a big compression on that area. Dr Ting has said that for now John will not be able to ride at Laguna Seca."

Attention has now turned to who will replace Hopkins at the American round after Kawasaki confirmed they will not be able to find a rider in time for next week's German Grand Prix.

Currently, Kawasaki is expected to lean towards hiring an AMA rider for the weekend, with Bartholemy revealing that Chaz Davies, Roger Lee Hayden and Jamie Hacking top his list of candidates.

"Basically for Germany we would like to keep the bike free because it will be difficult to find anybody. But our idea for Laguna would be to put one of our American-based riders on the bike, maybe Jamie Hacking, Roger Lee Hayden or Chaz Davies."

What is certain though is that Melandri won't be making the surprise switch from Ducati, where he has endured a tough season thus far. Although Bartholemy admitted that the rumours of Kawasaki approaching Melandri are true, he adds that it was dependant on him finding a solution with his current employers which he wasn't able to do.

"I said to him [Melandri] after I knew how bad John's injuries were, and told him that we have a bike free for the next two events, but that he would have to find a solution with Ducati, to get out of his contract. This is not a Kawasaki matter. But now they have told me that he will continue with Ducati for the next two races for sure."

However, unless there is a radical upturn in performance over the next two rounds, Melandri is still expected to separate from Ducati after Laguna Seca, leaving the former MotoGP World Championship runner-up free to pursue a Kawasaki seat from Brno onwards.

Melandri's former Gresini Honda team-mate Sete Gibernau is expected to replace Marco should the Italian leave.