Casey Stoner said he was quite content with his Ducati's performance in Motegi practice, but reckons it could turn out to be irrelevant if rain hits the rest of the weekend as forecast.
After being fastest in every session in Qatar, Stoner was only second today, although he had led the way until main rival Valentino Rossi put in a quick lap late on.
"We're not too far from setting some very decent lap times and considering how cold it was this afternoon I think everything has gone as well as we could have expected," said Stoner. "It looks as though the weather forecast is not good for tomorrow so this session might not turn out to be so important in terms of qualifying, but then if it's dry again on Sunday it could turn out to be crucial.
"In general the bike feels quite good – we need to try and find a bit more grip on the rear and we have a few ideas that we think could work – but now it's just a case of seeing what the heavens throw at us tomorrow and dealing with that as best we can."
His teammate Nicky Hayden was 1.8 seconds slower in 13th place, but played down his lowly position.
"We tried a few things out with the setup – I ran both bikes and worked in the direction we'd found in Qatar, where the balance of the bike had felt much better in the later laps, with less fuel on board," said the American. "Obviously the lap time isn't great but we improved with every run and pretty much every lap, we got a good number laps in just in case it does rain tomorrow and we worked out a basic direction we need to take for the race, so I'm satisfied."