 Pirelli found that 90% of the rear tyres used in free practice had been cut by the bolts securing kerbs to the ground not being drilled into the ground far enough, while Jenson Button and Nico Rosberg expressed concern over the lack of run-off areas which would be dangerous in the case of an incident such as a high speed puncture or mechanical failure.Valtteri Bottas was forced to miss the whole of Free Practice 3 when a drain cover came loose and caused significant damage to his Williams FW38.Many drivers praised the circuit for the challenge offered by its mixture of long straights, slow technical sections and no margin for error due to the proximity of the walls.