Marquez suffers leg break in training
The 21-year-old Spaniard broke his right fibula during a dirt-track session in Spain on Wednesday and has been ruled out next week's training event in Sepang.
Having undergone a CT scan and an X-ray at the Quiron Dexeus University Hospital in Barcelona, he was treated for a fracture to his right fibula.
Xavier Mir, the doctor who treated the Repsol Honda rider, predicts the current world title holder "will need three to four weeks to fully recover", with the first race of the calendar taking place in Qatar on March 23.
Marquez, who has already begun rehabilitation, is expected to recover in time for the season-opening event with the Spaniard explaining the break could have been much worse.
"It was a really unfortunate accident that could happen to anyone at any time," he said in a statement.
"I was rushed to hospital and Dr. Mir treated me; thankfully there was no ligament damage and it seems like a clean break."
Marquez, a rookie last season, will aim to defend the title he won by four points from compatriot Jorge Lorenzo.