Daniel Ricciardo says neither he nor Red Bull understand why they only had the pace to finish 13th in Montreal, the venue where he triumphed for the first time in Formula One racing last year.
After qualifying ninth, Ricciardo expressed his frustration that "we don't seem to be propelling forward at the moment" - a sentiment he repeated on Sunday after finishing a lap down and comfortably out of the points.
"It's been a strange weekend for me and I am a little confused about today's race," Ricciardo said.
"I was lacking pace and we are not sure why. There was nothing that felt especially wrong but we just couldn't get any pace out of the car.
Daniil Kvyat brought his RB11 home ninth, leaving Ricciardo scrabbling for answers to account for the gap to his team mate.
"I had a few set-up changes compared to Dany [Kvyat] but that doesn't explain the difference in pace," Ricciardo reflected. "It is something we will look at to understand what the cause was."
Team principal Christian Horner labelled Ricciardo's weekend ‘unusual', adding that it was "a difficult race for the team, as we simply did not have the pace to make any progress”.
"Dany did a very good job all weekend to salvage a couple of points and that was the maximum we could achieve today,” added Horner. “Daniel struggled for pace all weekend, which is unusual for him. We'll now have an in-depth look at that to see what might have caused it."
Red Bull leave Canada a lonely fourth in the constructors’ standings with 54 points, 50 behind Williams and 31 ahead of Sauber.