The Silver Arrows were no higher than third in both of Friday's sessions, with Hamilton ahead in FP1 and Bottas in FP2.

"We don't know how much the other teams can improve tomorrow, we for sure can," Bottas said at the conclusion of the day's running.

"We'll do the work as usual to try to still get the car better. It didn't feel good enough today, balance-wise."

Asked what exactly needed to be worked on, Bottas said: "We just really need to find the balance. That way you can trust the car and be consistent in qualifying and find the limits."

Hamilton, whose best lap of the day was on the soft compound as he couldn't get a clean push lap together on the supersofts, likewise reckoned the car balance wasn't "good enough".

He conceded that Friday running left the team in search of answers, saying: "Particularly FP2, started out good and then got a bit confusing later on in the session.

"It is very unclear at the moment as to where we need to change the car, there's a lot of analysis that needs to go on now - and hopefully tomorrow when we get out on track, it feels better."

Hamilton reckoned Mercedes' struggles on what proved to be "one of the harder Fridays" he's had at the Hungaroring could be down to the strong gusts of wind around the track, or the Pirelli tyres.

"We've got to do the work tonight because the car currently isn't in the right window. But I think we can get there, we've got the best team."

Top three "closest" in Hungary

Both of Friday's practice sessions were topped by Red Bull's Daniel Ricciardo, with a Ferrari driver in second and a Mercedes driver in third.

The Mercedes pair insisted that Red Bull's strong form in Hungary was no surprise, given the track layout.

"It's going to be a very close qualifying," Hamilton predicted. "This is the circuit where I think the top three teams are the closest, probably.

"The Red Bulls look like they have a little bit more downforce maybe, Ferraris are very, very quick, I would say we're definitely not as as quick as we were at Silverstone."

Bottas agreed: "It is going to be really close in qualifying and the long-run pace is really close between the three teams.

"We need to find every single hundredth we can tonight."

Despite the three teams being evenly-matched, however, Hamilton warned the race could very well lack in action due to the nature of the track.

"I think this weekend you'll probably going to see one of the closest battles time-wise, but it's very difficult to overtake here. So might not be the most exciting race necessarily, but qualifying should be exciting."