Yamaha racing boss Lin Jarvis wants the team's 2011 line-up to be finalised by Brno next month, and confirmed that Ben Spies will replace Valentino Rossi if the Italian's anticipated Ducati switch happens.
Rossi is now considered certain to line up with Ducati next season after seven years at Yamaha, with the announcement of this move also predicted to take place during the Czech Grand Prix weekend.
Jorge Lorenzo is expected to remain at Yamaha, and Jarvis said talks were progressing with a view to a 2011 announcement at Brno.
"There is a proposal and I could define the negotiations to be at a good point," he told Gazzetta dello Sport. "We'd like to have everything in place by Brno, in order to announce the 2011 team."
He insisted Yamaha had yet to receive a definite reply from Rossi regarding its offer for next season, amid rumours that the Italian had turned to Ducati after disagreements with Yamaha over pay.
"We've put up an offer on which we are waiting for a reply," said Jarvis.
"I can't supply details on the negotiations. But we feel the offer to be absolutely acceptable; obviously this is our evaluation."
If Rossi leaves, Jarvis said Yamaha would look no further than factory-contracted Tech 3 rider and 2009 Superbike world champion Spies.
"Should one of our two riders leave, he would certainly be in the works team," said Jarvis. "We are convinced we'll have a winning team in 2011 too."
Jarvis also confirmed that current title sponsor Fiat could depart Yamaha with Rossi.
"It depends on Valentino's reply," said Jarvis of Fiat's future with Yamaha.
"We already have a contract with Petronas for 2011, their effort and their space on the bodywork could increase. And we are also in talks with other companies outside motorcycling.
"We are not worried, but this will be the third step. The team comes first."