Injury blow for MotoGP leader Lorenzo

(CNN) -- Joint MotoGP leader Jorge Lorenzo is in doubt for Saturday's qualifying for the China Grand Prix after suffering ankle injuries during Friday's practice sessions in Shanghai.

The Spaniard sat out the afternoon session as he was taken to hospital for an examination which revealed he had chipped a bone in his left ankle and also damaged his right one, the motor sport's official Web site reported.

The Yamaha rider, level top of the world championship standings with compatriot Dani Pedrosa on 61 points after three races, is seeking to maintain his 100% pole position record this season.

"His right leg has been traumatized. It has very bad bruising to the tibia and heel," said team spokeswoman Katie Baines. "It will be very difficult to get him to ride tomorrow or Sunday."

Seven-time world champion Valentino Rossi, who trails by 14 points in third overall, was quickest on Friday after clocking a time of 1 minute 59.906 seconds in the morning.

Defending world champion Casey Stoner was second fastest on his Ducati, setting the quickest time of the afternoon session in 2.00.163.

The Australian is fourth overall, 21 points behind the leading duo after finishing 11th in Jerez and sixth in Estoril following his opening victory in Qatar.

Both he and Rossi had grip problems on their final outing of the day, avoiding highsides on the sun-heated asphalt but losing time making corrections.

Rossi -- who has not won for seven races -- ran off the track at one stage, as did Alice Team's Toni Elias and Rizla Suzuki's Loris Capirossi.

Pedrosa, who won his maiden MotoGP title in Shanghai in 2006, was third fastest in practice on his Repsol Honda.

Japan's Shinya Nakano was fourth fastest on a San Carlo Gresini Honda, while American rider John Hopkins was fifth on his Kawasaki. E-mail to a friend

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