Valentino Rossi described the psychological blow of his season-wrecking motocross accident as worse than the physical pain of breaking his leg.
The Movistar Yamaha rider, a seven-time MotoGP world champion, underwent surgery last Friday after suffering displaced fractures of the tibia and fibula of his right leg.
It will rule him out of at least the next two races, including his home grand prix at Misano this weekend, which scuppers the Italian's hopes of competing for the title this season.
"The leg is painful, but in general I feel good," the 38-year-old told the MotoGP website.
"It is a lot worse, the mental condition, because it was a great shame, throwing away the chance for the championship, and also the race in Misano in front of all of the fans in my home grand prix.
"I have to say sorry to my team that I don't race, but now we have to work for a comeback as soon as possible."
Asked when he might return, Rossi suggested he could be back for Motegi in October.
"It depends very much on the leg, very much on the pain," he said.
"We already work, we try to come back as soon as possible. The next race after Misano is Aragon, but I think that it will be very hard because that is just 22 days after the injury.
"We need double, or at least 40 days. Last time I came back after 40 days.
"This time the fracture is better, less painful, but it's very early to say. If I'm not able [to ride] in Aragon I will try for Motegi."