Russell was forced out of the race prematurely at Interlagos on Sunday after an issue with his engine started to worsen.
Mercedes pulled him out of the race amid fears that it would completely damage it and thus force him into using new components and potentially take grid penalties.
Confirmed by Mercedes’ head of trackside performance - Riccardo Musconi - Russell will be using a different power unit for Vegas and Abu Dhabi “as was originally allocated” clearly suggesting his DNF in Brazil hasn’t altered their initial plan.
“George will be on different power units for the next two races as was originally allocated,” Musconi explained in their post-race debrief on YouTube.
“The power unit used in Interlagos was meant to be its last race weekend so why did we retire his car?
“We started seeing some pressures and temperatures that were quite worrying and it got to a point where we were quite convinced it was about to fail.
“To avoid a possible fire and damage other parts of the car, the logical conclusion was to retire the car.
“He will be on a different power unit for the final two races so there is no issue from that point of view.”