Although unwilling to reveal precisely what its upgrade package consists of, as Williams seeks to close the gap to the midfield, Friday's practice sessions will see the team perform back-to-back tests as Robert Kubica tries the latest upgrades and teammate, George Russell continues with the previous-spec car.

"Hopefully this weekend will be the first time this year where we see a small step forwards," Russell told reporters, "how much that will be we're not sure yet, but definitely some visible changes to the car for this weekend.

"Robert will be running the new stuff tomorrow," he continued, "and I'll be running the previous stuff to get a full back-to-back correlation to see the differences, then I'll have it on my car for Saturday.

"It'll be a step forwards," he added, "but I'm still sure we'll be slowest still. This weekend is quite important for us to understand how these test items we're bringing to the car plan out, if they work as expected it would be positive for us.

"I won't give a figure on that in terms of a number, but we have some expectations of where we think how much it should improve by. If it reaches our targets we'll still definitely be slowest this weekend, but we know we've got more to come later in the year.

"Behind the scenes we're definitely seeing a lot of progress," added Kubica, "so we hope that translates on to the track as well.

"We have a few new bits on the car, which is a continuation of what we introduced a bit in Silverstone, which was focusing on getting the car faster, getting more downforce on the car and hopefully they will work as expected, should be a good improvement."

Check out our Thursday gallery from Hockenheim, here.