Valentino Rossi out for up to three months after crash
Valentino Rossi faces up to three months out after suffering a "very serious" compound fracture of his right shin in Italian MotoGP practice.
The reigning world champion crashed in Saturday's first practice session for his home race at Mugello.
"It's a more serious fracture than we expected," trackside medic Dr Claudio Costa told reporters.
"It's a compound fracture involving both the tibia and the fibula. I hope there are no complications."
Fiat Yamaha rider Rossi was fastest in Friday's practice session and third fastest in the Saturday morning session when he crashed 15 minutes from the end.
He attempted to stand up but was clearly in great pain and was taken away on a stretcher to a track medical facility where the injury was diagnosed, before being flown by helicopter to a hospital in Florence.
Yamaha team manager Davide Brivio said the 31-year-old Italian would undergo surgery later in the day.
"We have decided for him to be operated on immediately, but we won't rush his recovery time," said Brivio.
"It will be a normal recovery".
Coming into the weekend, Rossi was second in the standings, nine points behind team-mate Jorge Lorenzo, who has won the last two races.
Rossi was hoping for a 10th career win at his home circuit this weekend, to close the gap on leader Lorenzo, who was the fastest rider in the Saturday practice session.
How unfortunate for Valentino, at his home GP as well!! Hope he has a speedy recovery. I predict that Jorge will get his first championship now. its a shame that he will win it this way (well thats if he does win it), his and Valentino's battles on track were legend.
Stoner was struggling until he suddenly found form towards the end of the session, taking provisional pole until he was beaten by Lorenzo, who is 47 points clear of second-placed Dani Pedrosa in the championship standings.
And despite his surprisingly good finish, the Australian Ducati rider was not happy with his bike.
"We were struggling like hell with rear grip, it was spinning as soon as I touched the gas, no matter what we do we couldn't fix the problem," he told BBC Sport.
"I expected it to work better in these temperatures - we've got some work to do before tomorrow."
Stoner also had strong words for some of his fellow riders who had not got out of his way when he was trying to improve his lap time.
"Everyone seems intent on stuffing me up," he said.
"They look behind, see you coming and still don't get out of the way.
"I'm ready to put someone in a wall, I'm getting sick and tired of it - it's part of racing tactics, but what goes around comes around."