Lewis Hamilton was ready for "tough discussions" with Mercedes after Formula One's seven-time world champion qualified only seventh for the Monaco Grand Prix.
The Briton, who has made his best start ever to a season but whose 14-point lead over Red Bull's Max Verstappen could disappear in Sunday's showcase race, made his frustration evident.
Verstappen qualified on the front row and could yet start on pole position if Ferrari's Charles Leclerc needs a new gearbox after crashing.
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Asked by reporters whether he feared the next race in Azerbaijan could see a repeat, Hamilton shot back: "Not if I can help it.
"There will be some tough discussions that I'll have with my engineers, tonight or maybe after the weekend, because there's things that should have been done that haven't been done."
"We'll learn from it and we'll come together stronger in the next race."
Asked to expand on what had not been done, Hamilton said he could not say much about it.
"I don't want to be critical of the team, but behind closed doors I will be, and we've got to work harder."
Team boss Toto Wolff said Mercedes had failed to provide Hamilton, winner of three of the first four races, with a good enough car.
He said the immediate team discussion had already happened and the qualifying chapter was closed, with the focus now on Sunday's race.
"There was a lot of frustration. When you finish in P7 in Monaco you know pretty much that is potentially the end of the weekend," he said of a circuit where overtaking is nearly impossible.
"Venting your frustration is absolutely OK. Nobody in the team takes this the hard way because we express the other way around too."
'Car was really hard to drive' Hamilton on difficult Monaco qualifying
Wolff said there was one particular aspect of tyre heating that had been discussed after Thursday practice and on Saturday morning and where the team could have taken a different direction.
Hamilton, who had struggled throughout practice, had been interested in pursuing that but the team had not done so.
"That was exactly the content of our discussions now, how can we go into an exploration mode when we expect much colder temperatures," said Wolff. (Reporting by Alan Baldwin; Editing by Hugh Lawson)
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