Lewis Hamilton
Lewis Hamilton is leading the 2018 F1 Drivers' Championship by 14 points. In this picture, Hamilton of Great Britain and Mercedes GP walks in the Paddock during previews ahead of the Canadian Formula One Grand Prix at Circuit Gilles Villeneuve in Montreal, Canada, June 7, 2018. Mark Thompson/Getty Images

Mercedes will be the only manufacturer among the four — Ferrari, Renault and Honda being the other three — on the grid that will not run upgraded power units (PU) at the upcoming Canadian Grand Prix on Sunday.

The Silver Arrows team revealed earlier in the week that all six Mercedes powered cars on the grid will receive their second power units of the season in Canada, but have pushed it back to the next race after identifying a quality issue.

Lewis Hamilton, who was looking for his seventh win at the Gilles Villeneuve Circuit, is concerned about Mercedes’ inability to bring an upgraded engine to a circuit that is power sensitive. The Briton admitted it is possible they will not be able to fight for the win if their main rivals Ferrari and Red Bull Racing run upgraded PU’s in Canada.

The Italian manufacturer and Renault have confirmed upgraded packages for their respective works and customer teams, which could provide them with an advantage over Mercedes. The Brackley-based team will run the same engine that has run for the past six races, which could put them at a disadvantage in terms of horsepower on offer.

“This is a power circuit, so it was our target and it definitely would have been helpful,” Hamilton told Sky Sports on Thursday. “But the guys worked as hard as they could and had to take a sensible decision to not bring it here, which is definitely unfortunate, but we'll try and make do without. But it will mean our performance is probably not the greatest.”

“If the others are bringing upgrades and have got fresh engines, particularly how close we are, we won't be in position to fight for the victory. This is a power circuit and there is power lost over an engine [life],” the four-time world champion explained.

Teams are restricted to three power units for the 21-race campaign, which means each engine will have to last at least seven races. And Hamilton is concerned, not about the performance it will offer, but the reliability owing to the mileage it has already covered in the first six races this season.

Despite running an old PU, the British driver, who is currently leading the Drivers’ championship, made it clear he will race to win. But he is aware Ferrari and Red Bull will be strong with new upgraded engines.

“All I'm hoping for is reliability. If I'm on the seventh race with a difficult circuit on engines, I want to see it through. That's my main concern,” Hamilton added. “Naturally I'm still here to win but, as I said, if they've got upgrades on their engines, which are going to be a tenth to two tenths. Ferrari are particularly very strong on the straights, it'll be interesting to see if we are able to match them or not. But we'll give it everything, that's for sure.”