Paul di Resta has switched to a new chassis in Abu Dhabi in a bid to move on from a "fundamental" issue which had blighted his last few races. The Scot had previously told reporters that he was hopeful the issue had been solved.
Despite the switch, di Resta admitted there were still problems for him to overcome, namely making up the time lost when third driver Jules Bianchi took the reigns in first practice.
"We're not as concerned as we were – I think we have sorted it," di Resta confirmed in relation to his previous issue. "We're still trying to catch up though. It was quite a difficult day [with having] to miss a session, and it's very tricky to get the car in the right working window. We're a bit behind where I'd like to be yeah, but not concernedly so because I think its better to have that going in to tomorrow.
"In terms of the session we got through everything we had to achieve in the outline, so now we can sit down and really get into then nitty gritty of it ahead of tomorrow."
Di Resta stressed the importance of getting the tires into the right operating window, saying unlocking Pirelli's rubber would be fundamental to a strong weekend.
"We're going to need a step tomorrow morning for Q3 - our immediate competitors seem quite quick, and certainly Williams looks strong," he said. "I think there is a very narrow [tyre] window, and if you can get yourself in it you can go. I'm reserved at the moment because I have only done one session, and we know we have work to do.
"The car is moving about a lot here and they have changed the kerbs quite a lot so I think it is quite a different approach. Every session I went out I got better and by the long run it seemed to be a good step better again.
"The guys already have things written down to change it, and I think with overnight changes we should have a further benefit."