Sebastian Vettel ended Friday with a sizeable deficit to front-runner Lewis Hamilton's Mercedes, but says he is confident he "can do something" to challenge the leading Silver Arrows.
The Ferrari driver was Hamilton's closest rival on Pirelli's ultra-soft compound, but at a fair distance unfortunately with a 0.547s gap.
But the German is optimistic that more speed shall be extracted from his SF70H before tomorrow's running gets underway.
"Overall [the first day has] been OK, but we had some small troubles during first practice, which cost us some track time, so ,it took a bit longer to get into the groove," Vettel said.
"My car doesn't feel as good as it should or can, so I'm confident we can do something."
In reference once again to Ferrari's pre-season testing form and Lewis Hamilton's claims that he was playing his cards close to his chest, Vettel discarded any rival chatter.
"Obviously we've been very happy at testing, times look good, but it doesn't mean anything when you come here and that's when it matters, I think we were realistic about that.
"As I said today was OK, I think the car feels good. It hasn't changed much, I mean it's only two weeks ago we got out of the car but it's good to be back here and as I said we can still improve."
GALLERY: all the pics from Friday's action
Keep up to date with all the F1 news via Facebook and Twitter
Another qualifying session, another pole position for Max Verstappen. In Miami, the Red Bull charger…
George Russell believes that Mercedes’ struggles this season are rooted in the team “overcompensating” for…
Charles Leclerc insisted that he was driving right on the limit in Saturday's qualifying session…
It might look to others that it's been plain sailing for Max Verstappen this weekend…
Lewis Hamilton noted his progress in Saturday’s afternoon’s Miami Grand Prix qualifying, having reached contrary…
Max Verstappen will start from pole position for the second time this weekend, after calmly…