MotoGP World Championship leader Jorge Lorenzo suffered his worst start to a 2010 grand prix by being sixth fastest at the Sachsenring on Friday.
The Spaniard had previously never been lower than third during FP1, but finished first German GP practice 0.7sec behind nearest title rival Dani Pedrosa - and only 0.02sec in front of injured team-mate Valentino Rossi.
Lorenzo, who has won the last three races in a row at high-speed tracks, lacked confidence in the front end of his M1 in the slower Sachsenring corners.
"Today wasn't a good session for me and I didn't feel so good on the bike," he said. "This isn't one of my favourite tracks and it's very different to the ones where I've won lately, so I think I need to make some changes to the way I'm riding the bike.
"I was fast at the start but then we didn't improve from the middle to the end and everyone else did. We have some work to do and our goal is to be competitive by Sunday."
"It wasn't a great start for us, Jorge is struggling for feel and he can't turn so well, compared to 2009 here he's not in such good shape," confirmed team manager Wilco Zeelenberg.
"We need to compare the data and find out the differences, which are only small, but small differences always matter at this track because it's quite short.
"Hopefully if we can improve confidence in the front end Jorge will be much quicker, especially on the slow corners of which there are many here."
Lorenzo, who finished a close second to Rossi in last year's race, starts this weekend 52 points ahead of Repsol Honda rider Pedrosa.