Christian Horner confirmed to Sky Sports that Verstappen's RB18 had problems with temperature. The track temperatures in Miami rose to around fifty degrees Celcius during FP1. As a result, the Dutchman drove only fourteen laps and was mainly in the garage.
Verstappen will start the second session with a delay. The engineers at Red Bull are currently still working hard on the car of the Dutchman. The gearbox is changed as a precaution. During the first session Verstappen lightly hit the wall.
Red Bull wants to prevent DNF
"I've just had confirmation, following a brush with the wall, they have a precautionary gearbox change for Max Verstappen. They don't want another DNF. They were not freaked out by the Ferrari result in FP1, they have time in hand now they have a thinner rear wing to counter what Ferrari have. They seem chilled out and not fused about getting out which they can't as they fix the gearbox", Ted Kravitz says on Sky Sports.