Second practice in live on 5 live Sports Extra and the BBC Sport website from 15:00 GMT
Ferrari set a scintillating pace in first practice at the Bahrain Grand Prix, nearly a second quicker than the fastest Mercedes.
New Ferrari recruit Charles Leclerc was quickest, 0.263 seconds ahead of team-mate Sebastian Vettel and 0.974secs quicker than Valtteri Bottas.
World champion Lewis Hamilton was fourth, 1.247secs down on Leclerc.
It was encouraging for Ferrari, who were off the pace at the opening race of the season in Australia.
The Italian team had left pre-season testing with most of the grid feeling they had the fastest car but they finished the race in Melbourne a minute behind winner Bottas.
Ferrari have spent the period since then analysing the data from Melbourne and Vettel said: "There were a lot of thoughts and big analysis. The last couple of weeks have been very intense, we have some answers because we never get the chance to go back and repeat.
"We learnt some things about ourselves and the car that will help us to be more competitive but we are not in a position to be able to make promises. We need to wait and see."
Valtteri Bottas was third fastest in the first practice session
Initial indications from Bahrain are that Ferrari are back on form but the first session at the Sakhir track is never a good guide for weekend performance because it takes place in the heat of the afternoon, while qualifying and race are held at twilight and into the night.
Hamilton was on course to beat Bottas' time but he ran wide at the final corner on his best lap.
Red Bull's Max Verstappen was fifth quickest, 1.319secs off the pace and 0.142secs ahead of team-mate Pierre Gasly.
McLaren's Carlos Sainz was best of the rest in seventh, ahead of Renault's Nico Hulkenberg, Toro Rosso's Daniil Kvyat and Alfa Romeo's Kimi Raikkonen.
Racing Point's Lance Stroll was the only driver to crash, losing control at Turn Four early in the session and damaging his front wing on the wall on the inside of the track.
Williams' George Russell had a spin at Turn Two without damaging his car.
Williams, who had languished more than a second off the back of the grid, looked more competitive in Bahrain.
Russell, in 19th, was just over 0.6secs behind Stroll in 18th, and the Briton's team-mate Robert Kubica was just 0.065secs behind him.
And there was a clash between Hulkenberg and Alfa Romeo's Antonio Giovinazzi in a mix-up at Turn Seven, when the German turned into the Italian as he tried to pass.
Both have been called to race stewards over the incident.