Ferrari's Charles Leclerc says the Scuderia is seeking the best compromise between speed and tyre wear in Sochi, and the Monegasque is hopeful the team has found its way.
Leclerc topped Friday's morning practice as the SF90's aero package for Sochi was validated and then clocked in just 0.335s behind Red Bull's Max Verstappen in FP2, when the focus was on preparations for qualifying.
Overall, Leclerc was happy with how his day had unfolded despite the complexities linked with the team's search for the most balanced set-up.
"It was quite a good day," said Leclerc. "Although we have some work to do when it comes to our qualifying pace, our race pace was very positive.
"The track layout can be deceptive, as it has many similar corners. But it is tricky to set up the car, because the first and second sectors are quick and once you arrive in the third sector, the tyres are not in the best shape anymore.
"There is quite a difference in balance from the beginning to the end of the lap. You have to find a good compromise in the set-up, which will allow you to post the best lap time without sacrificing your race pace.
"We tested a bit in both directions today and I think we found our way."
Sebastian Vettel admitted that he had struggled in the afternoon session, but insisted it was early days still for Ferrari.
"My day was not perfect, as in the afternoon I struggled a bit to find the right balance and therefore I never got into a rhythm," said the German.
"I think we can do better tomorrow as we tried different things and now we need to decide what to keep and what to get rid of.
"I think we need to work more on the car and then we’ll see if we are competitive.
"It’s too early to tell what the pecking order is and we will get a better idea of where we are tomorrow.
"I don’t know what the weather is doing, but the closer we can be to the front the better it is. Anyway, we have the tyres for whatever the situation might be.
"To summarise I think we can improve, in particular in terms of balance. I hope tomorrow we are on the good side of things."