Following Max Verstappen's understeer issues in free practice, Christian Horner was saying littler, other than there's "a little bit of a balance mish-mash".

0.425s off his rival's pace in opening practice, the gap had extended to 0.635s by the end of the day, prompting fears that despite Lewis Hamilton taking a 10-place grid penalty, he could still come out on top of Verstappen in the race.

Throughout the second session, the Dutch driver complained of understeer issues, particularly mid-corner.

"We've got a little bit of a balance mish-mash," Horner subsequently told Sky Sports, taking technical insight to a whole new level.

"The circuit is a lot grippier than it was last year, I think we're just a little bit out of the window with Max on set-up," he added. "It's going to be a busy night burning the midnight oil with the engineers and back in Milton Keynes as well."

Asked if he is confident the team can get on top of the problem he replied: "I think so, it's just understanding the issue.

"We know we have a good car," he added, "so it's just a matter of getting into that window and I don't think we hit that today."

"Today wasn’t the best of days," admitted Verstappen. "We tried a few different things going from FP1 to FP2 but we’re still looking around for improvements as we don’t have a lot of data on these cars for this track.

"Of course, Lewis is taking a penalty on Sunday but we have to focus on ourselves, hopefully we can make improvements before qualifying as we have some challenges, we'll see what we can do."

"We expected Mercedes to be strong here, they are strong here," admitted Horner. "We're going to have to go some to try and capitalise on that grid penalty.

"Their car seems to have quite low degradation, it's quite soft on its tyres. This surface is temperature sensitive. And we can see with what they've done, it's become even more sensitive in some respects where the grip level has gone up, but the sensitivity is still there, so it's going to play a key role.

"And who knows there's a bit of rain around as well tomorrow, maybe even on Sunday, so it could be another thriller."

Check out our Saturday gallery from Istanbul, here.