Helmut Marko has told Sebastian Vettel it is time for him to "raise his game" and adapt to the new style of Formula 1.
Vettel's fourth successive title defence has not gone according to plan as the Red Bull racer has struggled to get the most out of his RB10.
The car's Renault engine has put the team on the back foot as it is down in power compared to the likes of Mercedes while reliability has also been an issue.
But despite the team's general woes, Daniel Ricciardo recorded the first victory of his Formula 1 career in Canada, making the most of a bad Sunday for Mercedes.
That result moved Ricciardo up to third in the Championship on 79 points while Vettel is fifth, 19 points behind his team-mate.
And with the Aussie edging Vettel in qualifying, races and the standings, Marko has revealed that he has already told his four-time World Champion to "raise his game.
"I told him: 'There are 50 engineers working on this engine and they can't sort it out," Marko said in an interview with the BBC.
"'You're a top driver, it's up to you. You have to do it.'
"If he can't sort out the car, the easiest thing is the driver. He has to raise his game."
The Red Bull advisor also admitted that the Bulls considered signing Lewis Hamilton when he went on the market after his six years with McLaren.
In the end, the team felt that Vettel and Hamilton would make for a difficult partnership.
"We were considering it, but we thought it wouldn't work," said Marko. "To be successful, you need a certain amount of harmony."