Valtteri Bottas faces a race against time to be ready for qualifying for the Mexican Grand Prix as Mercedes must change his power unit after FP3.
The Finn stopped on track with 15 minutes remaining in the final practice session with a suspected hydraulic issue (pictured), with the car not able to return to the garage until the end of running for work to start. That left Mercedes with just two hours to replace the power unit in order to be ready for the start of qualifying, which is at 1 p.m. local time.
Bottas will revert to the power unit he used in Austin, meaning there is no grid penalty for the change as it is an engine already in the Mercedes pool.
Aside from the issue for Bottas, Mercedes team principal Toto Wolff told Sky Sports the team is still not happy with its performance despite Lewis Hamilton ending up second quickest in FP3, just a quarter of a second off Max Verstappen having been over a second adrift on Friday.
“Drivers are not happy how the car is going — it’s sliding all over the place,” Wolff said. “We’ve clawed a bit back on the power unit but still there is a deficit so we are not in a happy place.”