Williams driver Valterri Bottas is remaining positive and expects a decent result on Sunday despite having a poor free practice two session.
"In the morning, with the soft compound, it was the best it was all day, by far, but in the afternoon the in-corner balance was not quite together, some entry issues, some snap oversteer in mid-corner and then understeer so, yes, we have some work to do.
"We have find the tools to try and bring the tyres up to temperature quickly," he added. "I think today the tyre warm up we had was not enough, because I could do two consecutive laps, with similar lap times, with the supersofts, which is not how it should be.
"In the afternoon, as soon as we went out, we started to struggle with the balance of the car. It’s difficult to say much because the wind direction is going to change completely for tomorrow.
"It was tricky with the wind. The first sector was good with the headwind but there was quite a bit of gusty tailwind and it was a bit of a problem. But tomorrow it’s going to be different, the wind direction will change 180 degrees, so it will make a difference in terms of balance and how the car feels, so whatever we do with the set-up it will be tricky tomorrow."
Bahrain International Circuit - Winter testing