Yamaha boss Davide Brivio insists the team is in no hurry to replace Valentino Rossi, and admits he would not replace him if it was not for contract issues.
Rossi is set to be out of action for months after breaking his right leg in a crash during practice for the Italian Grand Prix.
Brivio admitted there are no obvious candidates available to replace Rossi.
"If it was up to us we wouldn't replace Valentino, but the contracts force us to," Brivio was quoted as saying by Gazzetta dello Sport, which writes that Yamaha will not replace Rossi for the next two races.
"We have two test riders, but they are a bit slow, and to see an excessive gap among riders isn't nice. Unfortunately it's difficult to find an available rider at MotoGP level."
Gazzetta dello Sport also says one of the candidates to replace Rossi is Superbike rider Cal Crutchlow, while it is believed Tech 3 rider Colin Edwards is also among the favourites for the seat.
Yamaha crew chief Jeremy Burgess told the newspaper that he expected Rossi to be able to return to action for the Czech Grand Prix in August.
"I think that, if everything goes well, he'll be back in Brno. He may even do it for Laguna Seca, but there's no pressure," Burgess said.
MotoGP doctor Claudio Costa said, however, that only the latest technology would help Rossi come back ahead of schedule.
"I'm stepping off the pitch now, it's up to science to heal him," said Costa. "The recovery time to heal the fracture is what has been mentioned, four or five months. But I'm the race doctor: if someone wants to chase an impossible dream I think that we need hoping to make it come true.
"If Valentino goes the traditional way, then the hyperbaric chamber (for hyperbaric oxygen therapy - HBOT) is an option, but he doesn't need it at the moment. But if a rider wants to do the impossible, then it needs to be done."
Brivio added: "First of all let's think of a recovery from a human point of view, it's difficult to make predictions. In one and a half months we'll understand when he is ready."
"The title is lost, so to come back after three races of after seven makes no difference, just like it makes no different to end the championship in third or tenth place," Brivio told Motosprint.
"The only thing that counts is Valentino's health, since his career won't certainly end for this incident."