Sebastian Vettel is back behind the wheel of the Ferrari SF71H after a mammoth day on Tuesday because Kimi Raikkonen is too unwell to drive.
After racking up 171 laps and topping the timesheet at the Circuit de Catalunya, Vettel was due to take the day off and give his team-mate for some more mileage – but there has been a change of plan.
Vettel will now join Lewis Hamilton, who hands over to Valtteri Bottas this afternoon, and Fernando Alonso, who will be praying he can get a full day's work done in the McLaren after it broke down three times in the opening day of the second test.
Daniel Ricciardo is back in the RB14 after Red Bull changed their own schedule yesterday by bringing in Max Verstappen for another day-long session.
There will be no official lunch break on day two, with circuit officials wanting to maximise the track time available from 0800 GMT to 1700 GMT.
Ferrari – Vettel
Red Bull – Ricciardo
Mercedes – Hamilton/Bottas
Force India – Ocon
Williams – Stroll/Sirotkin
Renault – Sainz/Hulkenberg
Toro Rosso – Hartley
Haas – Grosjean
McLaren – Alonso
Sauber – Leclerc