George Russell believes that Mercedes' latest updates are producing gains, but not enough to outpace the benefits of its rivals' upgrades in France.
Russell concluded Friday's running at Paul Ricard fourth in the pecking order. In FP1, the Briton focused on evaluating Mercedes' changes, fine-tuning his car more to his liking in FP2.
However, like his teammate Lewis Hamilton, Russell felt that Mercedes had perhaps lost out overall relative to Red Bull and Ferrari in terms of pure pace.
"We only did five consecutive laps but we're also probably a bit further off the pace than what we had hoped for," commented Russell.
"We have work to do tonight here at the track and back at the factories. There's a lot to go over and we need to make sure we can optimise our pace for tomorrow.
"From the running today, it looks like we're finding time but all the other teams keep bringing updates too, and the whole grid moves forward.
"So, although we're finding time, our competitors do as well. And we need to look at the data to see if our upgrades are working as sometimes it's not as simple as just seeing it on the lap charts."
©Mercedes
Mercedes trackside engineering director Andrew Shovlin says the team's lack of long running on Friday didn't help it get a clear view of its deficit to Red Bull and Ferrari.
"For one reason and another, we didn't get as much work done on high fuel as we'd have liked so we don't really know how we compare to RedBull and Ferrari but we do at least look closer to them than to the midfield," said Shovlin.
"We're not expecting to be on their pace tomorrow, both those teams looks like they are very strong on a single lap, especially Ferrari but hopefully we can get a bit closer in the race on Sunday."
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