Valentino Rossi has backed MotoGP world championship rival Casey Stoner to provide the toughest opposition to his bid for glory in Sunday's German MotoGP race.
Stoner was untouchable on the opening day of practice, topping the timesheets in both sessions and the factory Ducati rider will start Sunday's 30-lap clash with a 21-point advantage over Rossi.
Fiat Yamaha rider Rossi shrugged off concerns over Michelin front tyre durability as he posted the second fastest time this afternoon, after he'd finished only eighth fastest this morning.
Less than two weeks after Rossi triumphed over Stoner in a thrilling fight between the pair at the Dutch GP in Assen, the Italian is expecting another titanic duel with his 21-year-old rival.
Twice in the last three races Stoner and Rossi have finished first and second including their race-long scrap in Barcelona last month.
And Rossi said: "I hope it's more like Assen than Barcelona. It's quite impressive the speed that Stoner has from the beginning and this is one of his qualities. This means also that the Ducati is very fast and a good balance from the beginning. Usually we need more time with the Yamaha to arrive at the right setting but we hope we can arrive at the same level. But yes it will be a strong battle."