(CNN) -- Dani Pedrosa sealed pole in Sunday's Indianapolis Grand Prix in a qualifying session marred with a number of heavy crashes. Yamaha Factory Racing's Jorge Lorenzo took second ahead of Monster Yamaha Tech3's Andrea Dovizioso. The first red flag of the session came after Casey Stoner suffered a suspected torn ankle ligament when he went off early in the session. Ducati's Nicky Hayden was thrown from his bike at the same corner as Stoner later in the day. The American was briefly unconscious at the side of the track, causing another red flag while he received medical attention. Valentino Rossi will start 11th after a disappointing session. Spanish rider Hector Barbera has been replaced in tomorrow's race by Toni Elias after it was confirmed he cracked three vertebrae in a crash during Friday's practice session. The race takes place on Sunday, starting at 14:00 local time .
Dani Pedrosa takes pole at Sunday's Indianapolis grand prix . Casey Stoner suffers suspected torn ankle ligaments in crash . Nicky Hayden thrown from bike, knocked unconcious . Hector Barbera suffered cracked vertebrae in crash on Friday .