Valtteri Bottas will serve a grid penalty at the Belgian Grand Prix after Mercedes confirmed he and Lewis Hamilton will both run new, upgraded specification power units.

Reigning world champion Hamilton will have a new turbocharger, internal combustion engine (ICE) and motor generator unit – heat (MGU-H) this weekend, while Bottas will have a completely new power unit with six fresh elements.

However, Bottas will exceed his season allocation as a result, meaning he is set to start Sunday's race from the back of the grid.

Mercedes confirmed the news via Twitter on Friday as the first free practice session took place.

They also revealed the two other Mercedes-powered teams – Racing Point Force India and Williams – will run the same upgraded specification power units at Spa.

Renault's Nico Hulkenberg will join Bottas in starting from the back row on Sunday. The German is another who will carry a completely new power unit this weekend.