Sebastian Vettel believes Ferrari's gap to Mercedes in practice was highlighted by poor car balance at the Australian Grand Prix.
Tipped to take the fight to Mercedes following a strong pre-season testing program, Ferrari ends the opening day of the new Formula 1 season well shy of the Silver Arrows.
Vettel emerged as Mercedes' nearest rivals although the German was 0.5s shy of Lewis Hamilton, who topped both 90 minute practice sessions.
The four-time world champion felt the team had missed the window with the balance of SF70H, but expects an improvement in practice and qualifying on Saturday.
“The balance wasn't yet where I want it to be, so I think we can still do a decent step forward,” said Vettel.
“The car still doesn't yet feel as good as it should and it can.
“This morning was not so good, we had some small issues that caught me out. But the team is doing well. I think we have a lot of things that we can improve.
“The balance is not so good yet, but I'm sure we can work on that overnight.
“We had some small troubles this morning that cost us some lap time, so it took a bit longer to get into the groove.
“Obviously, we've been very happy in testing, the times looked good, but it doesn't mean anything.
“You come here and that's when it matters, we were realistic about that.
“Today was okay, the car feels good and it hasn't changed much, it was only two weeks ago that we got out of the car. We can still improve.”
In contrast, Hamilton produced an ominous performance in the Mercedes W08, setting a benchmark 1:23.620 in the final session on Friday.
The three-time world champion downplayed Mercedes' hopes heading into the season opener which left him pleasantly surprised by the pace he was able to extract.
“After struggling with some issues in Barcelona, we didn't know if we'd have the same thing here,” said Hamilton.
“What's really encouraging is that we've arrived at the track just a week later and the car is exactly where it should be.
“It's feeling great out there and the guys have done a fantastic job.
“We've shown good form so far on both the long and short runs and we got every lap done that we wanted to.”
Action will continue on Friday with final practice scheduled for 1400 local time.