George Russell says Mercedes has some "work to do" on Friday evening to try and claw back the ground lost on its rivals between the day's two practice sessions.
Russell and Lewis Hamilton had clocked in third and fourth at the end of FP1, with the former just 0.279s adrift of Ferrari pacesetter Charles Leclerc.
Carlos Sainz picked up the baton from his teammate in FP2, and while Mercedes' drivers went quicker in the second session, as did almost the entire field, the gap to Ferrari's chargers increased to over 0.7s leaving Russell and Hamilton respectively P5 and P7 as the pair was also overhauled by McLaren's Lando Norris.
"FP1 was looking pretty strong but then Ferrari and Red Bull seemingly have taken a step forward compared to us or maybe we’ve taken a step back as we were obviously behind the McLaren in FP2," commented Russell.
"So a bit of work to do tonight to understand that."
"We made some set-up changes, nothing major, but we went a lot slower somehow," added Hamilton.
"Or they went a lot quicker. [We were] giving it everything out there, it just doesn’t feel particularly quick."
Both Russell and Hamilton reported a lack of deployment in FP2, a weakness that likely contributed to Mercedes meager progress.
"It was a blip during the session, which made things worse," said Russell. "But generally speaking, we’re lacking a bit of deployment.
"I think we’re similar to Red Bull but Ferrari seemed to have the upper hand in terms of deployment.
"So that may make things trickier in a race scenario as they’ve got a bit more in the locker to play with. It’s going to be something we’re going to have to deal with.
Mercedes trackside engineering director Andrew Shovlin said the team's direct rivals had managed to extract more pace from their contenders than the Brackley squad.
"In terms of pace, it looks like our competitors found more between the sessions than we did so we need to look through that in detail to understand where we have lost out," said Shovlin.
"We'd expected this weekend to be tough as the car is very similar to the one that we had in Spa and with Lewis's power unit penalty, we've got a lot of ground to make up in the race before we can get him into the points.
"However, the goal remains to score well with both drivers and the fact that we had the car in a good place in the first session gives us some encouragement that we can get it back in that window."
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