Verstappen, who started from the rear of the grid at the Monaco Grand Prix after a crash in final practice, offered the promise of something much better in Montreal, taking full advantage of an upgraded power unit to put down two polished performances on the 2.7 mile (4.34 km) sun-splashed Circuit Gilles Villeneuve.
"It's positive that Max's pace is good", he added.
"We have got the pace in the vehicle to challenge for pole, but we are not really getting the best out of the hyper-softs", said Mercedes team chief Toto Wolff.
Max Verstappen completed the second training session in Montreal on the top line of the Protocol.
Mercedes ace Lewis Hamilton, who was fourth at 1:12.777, has won the Canadian Grand Prix six times, including the last three, and needs one more win to equal Michael Schumacher for the race record. One-tenth of a second separated the top four drivers including Ferrari's Kimi Raikkonen and current points-leader Hamilton.
Come qualifying, Ferrari and Mercedes upped their game - as they've done at each race weekend this year courtesy of their superior engine modes - with Verstappen the best-placed Red Bull in third.
"I would say Merc are going to be the favourites" said Ricciardo.
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Stroll, in his second season with Williams, posted the 19th fastest time of 1:14.703, outpacing only his Russian teammate Sergey Sirotkin.
Ricciardo will start the race on the softer hypersoft compound tyre, as will Verstappen in third place - whereas the Mercedes and Ferrari cars will all line up on ultrasofts.
His outlook had improved on Friday after leading in practice for the first time this year. His best lap was the slowest in the field at 1:17.145, but he was there just to get the feel of an F1 vehicle and help the team test it on two types of tires.
"We feel it's a good tyre for us and, in the long run, I felt good on it - so yeah, no big surprises", he said. The main thing was to get through the program, which we did. So qualifying we actually made really good progress.
But after the dreary spectacle in Monaco a fortnight ago, at least we can rely on one of the finest overtakers in the sport fighting his way back through the field to provide the entertainment this weekend.
The afternoon practice session, like the morning one, delivered two major incidents when Spaniard Carlos Sainz smacked the wall in his Renault, bringing a red-flag interruption for seven minutes, and later when Belgian Stoffel Vandoorne went into the barriers at Turn Eight, breaking the suspension of his McLaren.
He has raced in the F2 series the last two seasons and now sits 10th in F2 standings after eight races this year, including a third-place finish at Baku, Azerbaijan.