Casey Stoner hopes Valentino Rossi will mount a challenge in 2012 . Seven-time MotoGP champion Rossi without a win for Ducati last year . The Italian has won the past two races at Mugello and Misano but is yet to score points this season. Australian sees Jorge Lorenzo as his main rival in coming season .
Casey Stoner hopes Valentino Rossi will mount a challenge in 2012 . Seven-time MotoGP champion Rossi without a win for Ducati last year . Stoner claimed second title with 10 wins for Repsol Honda . Australian sees Jorge Lorenzo as his main rival in coming season .