Hamilton and Russell qualified fourth and fifth respectively in a chaotic wet qualifying in Montreal, in which the pair were briefly under threat of not making it into Q2 amid ever-changing conditions.
They will both move up a place after a penalty for Haas driver Nico Hulkenberg, who starred with a second place in Q3 but was later demoted for a red flag infringement.
Earlier this month both Mercedes drivers flanked Max Verstappen on the podium in Spain, a breakthrough result that vindicated the Brackley team's mid-season change of car concept.
Russell thinks he and Hamilton have found the race pace to repeat that performance on the vastly different Circuit Gilles Villeneuve.
"P5 is a good place to start from and I see no reason why we can't fight for a double podium again," Russell said when asked by Motorsport.com about the team's prospects in the race.
"On race pace we were really strong [in FP2]. Ferrari looked surprisingly competitive in their long run pace, maybe question marks over their fuel load.
"But we were just a small step behind Verstappen, ahead of [Fernando] Alonso, ahead of [Sergio] Perez at least yesterday in FP2.
"Signs are promising going into the race."
Friday's second practice session was the only opportunity to drive on a dry track this weekend.
When Motorsport.com asked Hamilton how many unknowns Mercedes was still facing over its race pace ahead of what is expected to be a dry grand prix, he replied: "Not too many.
"We had a long run yesterday, but it was at the beginning of the session when the track was much slower.
"I think the others did their long run like 45 minutes later. We'll wing it and see how it goes.
"Hopefully our race pace is stronger than what our pace showed today, so hopefully we're fighting the top two drivers Alonso and Max tomorrow.
"Hopefully we can put some pressure at least on one of them."
