The president of motorcycle racing's governing body, the FIM, has called for major changes to MotoGP in order to safeguard its future.
In the wake of Kawasaki's departure from MotoGP, FIM president Vito Ippolito said he is concerned that further withdrawals could cause major problems in 2010.
The manufacturers met in Japan last week to discuss cost cuts, but no concrete proposals have emerged so far, and Ippolito believes the time has come to re-think the technical concepts behind MotoGP so that budgets can be dramatically reduced.
"The problem isn't 2009, when one way or another we'll manage to have a full grid, but it's 2010," he told Corriere dello Sport.
"There's the risk of more defections, especially among privateers, who could leave us with just 14 bikes.
"That's why I'll repeat to the Japanese manufacturers the absolute need for going back to the past. That is going back to the building and selling of 'road production prototypes', like the ones that used to be raced in the eighties.
"The FIM will speak through a press release next Monday."
Dorna is working to place the factory Kawasakis with a private team to ensure that the grid stays at 19 bikes - which would be one more than in 2008 due to the arrival of the Onde 2000 Ducati team.
Kawasaki's exit leaves just Ducati, Yamaha, Honda and Suzuki as factory entrants, with all bar the latter also supplying at least one customer squad.
Ippolito added that he opposed moves to create more separation between MotoGP and the supporting 125cc and 250cc world championships, and urged the teams and Dorna to plan for the sport's long-term future.
"The sport needs the FIM, as motorcycling can't be just business," he said. "That's why I'm openly against the split paddock set up by Dorna: the world championship isn't just MotoGP, there are also the other series.
"Innovating is fine, but we also need to think long term and lower the costs."