Nico Rosberg has suggested Ferrari's performance at the Canadian Grand Prix may well be a one-off.

Sebastian Vettel claimed his first pole since Hockenheim last year on Saturday after beating Lewis Hamilton in qualifying.

However, rather than be a signal that the Italian team is overcoming their issues, the 2016 champion actually believes it proves Ferrari's problem.

“What you need to understand is they [Mercedes] built their race cars for the average track. That’s like between Monaco and Montreal; Monaco being really slow speed and Montreal being just high speed and straight lines," Rosberg said in a YouTube vlog.

“You have to build the car so it’s average and ideal for all tracks right in the middle. Then of course for Monaco it’s not going to be ideal, it’s just slow speeds so you need max downforce and Montreal isn’t ideal either because you need to be faster on the straights.

“This is where it was clear again today how Ferrari just got their concept wrong on their car.

“As soon as you go to one of the extreme high-speed tracks like Montreal, of which there’s only two because there’s only Montreal and Monza, boom they’re in front again and the fastest car – but only just.

“Then when you go to Monaco, the other extreme, they’re just nowhere. All the other tracks in the middle as well, they’re just struggling.

“They need to bring more downforce to the car and take away some of that straight-line speed but it takes time to change the concept like that. It takes a lot of time so they need to get on top of that very, very quickly," he concluded.

That being said, Rosberg was pleased to see Vettel break a long poleless streak, dating back to Hockenheim last year.

“Proper awesome lap from Vettel, after so many difficult races and the whole difficult start of the season and everything, so much pressure from Leclerc as well," he said.

“He absolutely bombed it, it was a beautiful lap, perfect. Two-tenths quicker than Lewis, six-tenths quicker than Leclerc, fantastic.

“I’m really, really happy for Vettel actually. For his mental game that’s going to be really, really crucial and it gives him a great opportunity to win so that’s really powerful.”

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Looking ahead to upcoming circuits at Paul Ricard, the Red Bull Ring and Silverstone though, the former Mercedes driver expects the domination of the Brackley-based team to return.

“Are Ferrari back? I don’t think they’re back,” he said. “On this track they’re back, everywhere else they won’t be. That’s a pity and they still have a lot of work to do.”