Lewis Hamilton is "likely" to take a grid penalty at this weekend's Belgian Grand Prix, according to Mercedes.
Reigning world champion Hamilton suffered from reliability issues at the start of the season and has already used his allocation of five penalty-free changes to two of the six power unit elements.
The Brit received his fifth MGU-H and turbocharger at the Austrian Grand Prix in July, meaning one more change of either component will incur a grid penalty of at least 10 places.
A five-place demotion is then imposed when any other element is switched for a sixth time.
Having built a 19-point lead over team-mate Nico Rosberg in the drivers' standings ahead of the mid-season break, Hamilton is expected to take the hit in one swoop at Spa-Francorchamps this weekend by introducing two new parts simultaneously in Belgium.
However, confirmation is not expected until Thursday.
"[An engine penalty] is likely. We will be able to say if penalty [or] not penalty tomorrow [Thursday]. And then over the weekend exactly what penalties will apply," a Mercedes spokesperson told Omnisport.