Valentino RossiValentino Rossi put his lack of pace in Indianapolis Grand Prix practice down to issues with his Yamaha's set-up rather than any lingering problems from his injuries.

The world champion was fifth quickest today, 0.7 seconds off pacesetter Casey Stoner's Ducati, but had been back in eighth for most of the hour.

He insisted he was not in any significant discomfort from either his healing leg or shoulder, and was just not quite on top of his setup yet.

"My physical condition is much better here," said Rossi. "I do still have some pain but it's not too bad so I am not worried.

"I am feeling confident on the bike but we have to improve our setting in order to improve our pace because we are lacking some grip here. It's not an easy track because there are a lot of bumps. We did quite a lot of work today but it wasn't enough and the gap to the top is too much.

"Our target for tomorrow morning is to close this gap so that we're in better shape to push for a good position on the grid."

Rossi's team manager Davide Brivio said he was not concerned yet and remained optimistic that his side of the garage would make a breakthrough in second practice tomorrow morning.

"We struggled a bit today and we need to do some more work to try to find the right package for this track," said Brivio. We started with our standard setting and now we need to continue to try to make it work how we want. It's just the first session so we have time. There is nothing very specific, we're lacking some grip and so we need to make the tire work better for us."