Robert Kubica is hoping that Williams will be able to "play" with its 2019 car at the final two days of testing this week.
The Grove squad is on the backfoot after it missed over half of the opening week of running last week. However, during test two, it has been able to clock over 100 laps on both days, with George Russell at the wheel of the car on Tuesday.
Kubica took over driving duties on Wednesday and will conclude testing for Williams in two days' time. The Pole is hoping that before the eight days of season preparation ends, the team will be able to experiment more with the car and get a true understanding of its pace.
"It was a normal day of testing," Kubica said. "Unfortunately, we are running a bit late with our test programme because of last week's issue, but its a bit of a mixed feeling.
"On one hand, it's positive that we did a lot of laps, but from the other side we're missing a lot of time. So, we are not in the position we want to be, especially from my side and an engineering point of view.
"We are doing a lot of data gathering, checking a lot of stuff. I hope the next two days, we can play a little more with the car and see how it reacts to different things.
"My aim is always the same - to do what I'm asked and do to the best I can do. In the end, there are some priorities. Going to Australia without a lot of testing is not helping, but that's reality. I have to make sure I maximise my time in the car."
Kubica's F1 return comes after a life-threatening rally crash in 2011 left him with severe injuries, which resulted in the partial amputation of his right forearm. However, the 2008 Canadian Grand Prix winner says that the injuries are not affecting his driving.
"It feels good. I feel I'm in the position where I should be. Again, driving more will help because in the end, you can prepare as much as you like in doing exercises, but driving an F1 is a different story.
"The body will adapt and react, and we did a lot of laps today without any issues, so I'm happy frmo a pohysical point of view."