Helmut Marko has warned Ferrari and Mercedes that, while they brought the gap to Red Bull down in Canada, the World Championship leaders were not at their best.
Max Verstappen complained throughout practice about poor downshifts within his Red Bull RB19, struggling to get to grips with how his gearbox was handling on Friday and Saturday.
Verstappen and team-mate Sergio Perez were down in sixth and eighth after qualifying simulations in FP2 on Friday, but Verstappen flew back to form in a wet qualifying session on Saturday and took a dominant pole position by more than a second around the Circuit Gilles Villeneuve.
While the reigning World Champion took another win on Sunday, his victory was by 9.5 seconds from Fernando Alonso in dry conditions when his last two came altogether more easily, by 27 and 24 seconds respectively in Spain and Monaco.
Red Bull motorsport advisor Marko admitted he was concerned by Ferrari and Mercedes on Friday after their trouble in practice, but assured that it was simply an off-weekend from their point of view.
"Yes, they did come closer here, but we didn't perform as we should have," Marko told the F1 Nation podcast.
"We couldn't bring the tyres on [to] temperature, especially the hard tyre, we couldn't get the right temperature.
"Everybody thinks the Red Bull is fantastic. Yes, it's a good car, but Ferrari and also Mercedes - they didn't improve from last year; I think they reversed in the beginning of the season.
"So, when we are not at our best, they are nearer. It's as easy as that."
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Verstappen himself admitted generating tyre temperature was a difficult task for the Red Bull, and he in fact drove for most of the race with a dead bird lodged in his car after colliding with the unfortunate creature while driving.
While the margin of victory is less than he has become accustomed to this season, he was pleased to get over the line for a fourth win in a row first and foremost.
"Firstly, I expected more or less what we had today, but it was, like I said, really difficult to just keep the grip, the temperature into the tyres, because the grip was disappearing very quickly. That's why maybe the gap was not that big," he said after the race.
"But yeah, we had a few Safety Cars here and there. But yeah, overall, we won, that's the most important."