Casey Stoner put his lack of speed in Friday practice at Misano down to having missed the event in 2009.
Last year's San Marino Grand Prix was one of three races that Stoner sat out as he recovered from an illness that had hampered his performance for much of the season.
He believes set-up data from that race would have helped him get on the pace today, when he ended the practice hour only eighth.
"That was a difficult session for us, basically because we didn't have any information from last year because I didn't race here," said Stoner.
"The characteristics of the current engine are very different to the one we used in 2008 so it requires a completely different gearbox set-up and obviously that affects a lot of different things.
"We took a bit of a shot in the dark with what we thought would work but unfortunately it wasn't quite right and we had to spend a lot of time today making adjustments.
"Hopefully the data we gathered can give us a much better idea of where to start from tomorrow and I'm sure we can quickly close the gap to the guys at the top."
Stoner's team-mate Nicky Hayden was one place ahead of him, having also had a tough Friday.
"That wasn't the smoothest session we ever had and I'm losing a lot on T3," said Hayden. "I hoped to start out a bit closer to the top than that. We need to look for some tenths, maybe by finding some better turning in the front and also adjusting the gearbox a bit better.
"To be honest it's not one big area we have to improve very much but small improvements in a few different areas.
"We also had a little issue with the fairing, which came a bit loose and my leathers got caught on it so I had to get back to the pit. We were trying something and after that I had basically one chance to make a good lap so we are not sure it is the right direction, which was a bit of a bummer."