Russell top as Verstappen hits trouble and Sainz crashes
Russell put his upgraded Mercedes on top of the FP2 order by 0.106s from championship leader Charles Leclerc, who was quickest for Ferrari in the opening session.
Red Bull’s Sergio Perez was third, ahead of seven-time world champion Lewis Hamilton, who ended up 0.241s adrift of his teammate as Mercedes enjoyed their best practice session of the season so far.
The new street track around the Miami Dolphins’ Hard Rock Stadium once again proved a test for the drivers, with Ferrari’s Carlos Sainz becoming the latest to crash as he hit the wall at Turn 14.
Sainz, who is badly in need of a clean weekend after a string of difficult races, lost control under braking as his car swapped ends and clattered the wall, causing the second red flag of the day and the first of two stoppages in FP2.
Meanwhile, Max Verstappen, Leclerc’s main title rival, endured a troubled afternoon and failed to complete a single lap after suffering reliability issues on his Red Bull car.
Following a precautionary gearbox change on his car after a brush with the wall in first practice, Verstappen had only just made it out onto the circuit when he was immediately forced to return to the pits with overheating rear brakes.
Verstappen reported a problem with his steering on his outlap before smoke was seen coming out of the rear of his RB18, later turning into a small fire.
The setback - which Red Bull put down to a hydraulic issue - has left the reigning world champion on the back foot and with a lot of work to do going into qualifying day on Saturday.
Fernando Alonso posted a lap within half a second of Russell’s benchmark to wind up fifth-fastest for Alpine and a tenth clear of McLaren’s Lando Norris.
Pierre Gasly, Guanyu Zhou, Esteban Ocon and Kevin Magnussen completed the rest of the top 10 for AlphaTauri, Alfa Romeo, Alpine and Haas.
Nicholas Latifi caused a brief second red flag when he pulled over in his Williams after questioning whether his left rear had been properly fitted and then losing drive.
Following his crash in FP1, Valtteri Bottas failed to participate in second practice with his Alfa Romeo team short of spare parts after problems at the last race in Italy.