"We expect a number of teams to take their scheduled second Power Units this weekend, including all the Mercedes-powered cars", Wolff said, as quoted on Sky Sports. "But we also know that the battle is fiercer, with ourselves, Ferrari and Red Bull in the contention for race wins every weekend; there is not a moment to relax".
"Montreal is a venue that nearly always delivers an action-packed race", said Mercedes team boss Toto Wolff.
The plan for the works cars was to switch to the new specification for Canada and then use the original units again for a seventh time in Hungary, a track where ultimate power counts less than elsewhere.
The Scuderia could also face a reduced threat from Red Bull as their auto is likely to be less suited on the long straights, though will be strong in the many heavy braking zones.
Renault and Honda have confirmed updates to their engines for this weekend and Mercedes had planned to bring the next step in its development to Montreal. This was because, new parts were required to fix an engine problem that the Australian suffered in Monaco.
"It's a great track and a real test for the driver and the auto".
The race takes place Sunday in Montreal.
Droves of race fans and drivers will soon be Montreal-bound to enjoy Grand Prix weekend, but one of the most notable auto companies seems to be a little confused about which city they're actually heading to.
"This was one that got away and it's a bitter pill for us all to swallow", Wolff said.
Asked if he expected Ferrari to have an advantage in Canada, Hamilton replied: "Yeah, and then also particularly if they do bring their upgraded engine".
The big loser could well be McLaren who have been the slowest in a straight line throughout this year and are unlikely to make up that deficit in other areas.
Toro Rosso's performance will also be engine based despite a good showing on a similar track in Bahrain back in April, but with Honda bringing upgrades reportedly worth almost 30 more horsepower, if reliable it could be a big step forward.
In the morning session, Williams driver Sergey Sirotkin spun and hit a wall, but was able to continue.
That is your look ahead to the possible stories to follow this weekend in Canada.
The team's struggles with the "hyper-soft" tyre in Monte Carlo undermined them in qualifying, but their strategic approach enabled Hamilton to finish third and extend his record run of points-scoring races to 31.
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