Ben Spies has warned that it will be impossible for him to replicate his World Superbike form in his first full season of MotoGP racing.
The 25-year-old American stormed to the WSBK crown in his rookie season this year with 14 wins for Yamaha, and has a wild-card entry in this weekend's Valencia Grand Prix alongside regular riders Valentino Rossi and Jorge Lorenzo ahead of a full season with Tech-3 in 2010.
But Spies said that the difference in riding style between the two classes and the quality of rider in grand prix racing would make running at the front a tough task.
"For us to do what we did there is impossible," said Spies. "We had a hard year and I had to fight, but the aim every weekend was to win. It just won't happen here. This is a totally different ball game.
"Most people don't really understand just how fast these guys in this championship really are. I understand it because I've already done a couple of races against them [for Suzuki in 2008].
"I know that this weekend and next year are going to be about learning, about me trying to evolve as a rider. There's a way of riding a superbike, and it won't work on these machines, so that's something I can improve on. Honestly, if I see a podium next year, that would be a miracle."
Spies said that he had asked Yamaha for a wild-card entry at Valencia upon signing his Tech-3 deal to replace James Toseland next year.
"When we made the decision to come to GPs a few months ago, I decided that a wild card would be a good thing to do, because with all the testing limitations at the moment, it's three days more on a bike," he added.
"It also means that the test on Monday can be a proper test, rather than just poking about. I can know by then how the tires are supposed to feel, for example. It's just one more thing I don't have to learn. I know I'm going to just keep riding and riding and work with it."