Mercedes has slightly turned down the power of its engine units for Sunday's Abu Dhabi GP amid concerns surrounding the reliability of its MGU-K component.
Engines are on their last miles as F1 reaches the end of its season, increasing risks of break downs. Racing Point's Sergio Perez suffered an MGU-K failure in the Bahrain GP as a podium was in sight.
As a measure of precaution, Mercedes has lowered the output of the component on all its engines for F1's finale at Yas Marina.
"We've got a bit of a gremlin sitting in there," said Mercedes F1 boss Toto Wolff.
"The MGU-K is below the power that it should normally give. We don't understand exactly why yet. So we've taken a bit of performance out of it, on all the Mercedes engines."
Racing Point is running new elements on Perez's power unit, but the changes entailed a grid penalty meaning that last weekend's Sakhir GP winner will start the Abu Dhabi GP from the last row.