HIGHLIGHTS: Watch all the key action from the opening practice session of the Sakhir GP

Earlier this week George Russell thought he would be driving a Williams in this weekend's Sakhir Grand Prix, but after Lewis Hamilton was ruled out having tested positive for Covid-19, Russell was called up to slot in as his replacement at Mercedes – and he looked like he was instantly up to speed with his new car by setting the quickest time of all in first practice.

It was a step into the unknown for all the drivers on Friday afternoon in Bahrain as they took to the super-fast Outer Loop track at the Bahrain International Circuit for the first time ever.

FP1 REPORT: Russell impresses with quickest time on first Mercedes outing as drivers get to grips with Bahrain's Outer Loop

And Russell was straight on the pace as he led Red Bull duo Max Verstappen and Alex Albon in the timesheets, with Valtteri Bottas fourth-fastest in the second Mercedes.

There were also two debutants in the field, with Jack Aitken subbing in for Russell at Williams, and Pietro Fittipaldi slotting in at Haas, as Romain Grosjean continues his recovery from his huge crash in last week's race.

Hit play in the video above to see how the new boys – and everyone else – got on as they got their first taste of the Outer Loop track.