The Mercedes-GP team have had to change the gearbox on Bottas's car, meaning the Finn will drop down the grid for Sunday's race.
British GP talking points: Role reversals for Bottas and Hamilton as Red Bull impress
Ahead of qualifying for the British Grand Prix at 4pm UAE time on Saturday, here are some talking points and things to watch for at Silverstone.
Change of fortunes at Mercedes
In Austria last weekend it was Lewis Hamilton who took the pain of a gearbox change, resulting in a five-place grid penalty. Now the boot is on the foot of his Mercedes-GP teammate Valtteri Bottas. The Finn, despite topping the times in both Friday sessions will be able to start no better than sixth for Sunday's race. It is a blow for Bottas, who had raced so well in Austria, but it should give Hamilton a free run to take the 67th pole position of his career and put himself in a strong position to revitalise his championship challenge.
Red Bull's promising pace
Red Bull Racing, particularly through Max Verstappen, were impressive in practice and very close to the pace of the Ferrari cars. The sweeping turns of Silverstone have always suited Red Bull, and Verstappen and Daniel Ricciardo, who is bidding for a sixth successive podium this weekend, have a decent chance of being on the second row.
Best of the rest is close
Nico Hulkenberg's Renault was seventh and the fastest driver not racing a Mercedes, Ferrari or Red Bull. He will face stiff competition from the Williams, Force India and Toro Rosso cars to repeat that feat in qualifying, especially with the Renault engine still lacking horsepower compared to the Mercedes units.
More woe for Alonso
Given just how little grunt the Honda engine has, the fact Fernando Alonso was ninth in practice for McLaren was yet another demonstration of the fact the double world champion's talents are being wasted. He has won the British Grand Prix twice in the past, 2006 and 2011, but it will have to be a very freakish race for there to be be a third success on Sunday as he will start last due to grid penalties for changes and alterations to his Honda power unit.