Lorenzo injured in practice

Joint championship leader Jorge Lorenzo has suffered a chipped bone in his ankle after an accident in Friday's opening practice session for the Shanghai MotoGP.

The Fiat Yamaha rider did not return for the afternoon session and is now a major doubt to complete the remainder of the weekend.

Circuit doctor Claudio Costa said: "Jorge now faces a very difficult task to participate in Saturday's qualifying and Sunday's race."

The rookie rider's accident could benefit arch-rival Dani Pedrosa (Repsol Honda), who currently shares the championship lead with Lorenzo on 61 points and came third in each of Friday's practice sessions.

Those sessions were split between two former champions, with Italy's Valentino Rossi fastest in the morning and current title-holder Casey Stoner (Ducati Marlboro) taking the honours in the afternoon.