Toto Wolff conceded Mercedes' car is a "nasty piece of work" as Lewis Hamilton 's difficult season continued in Miami.
Hamilton, a multiple world champion, has yet to win a race in the 2023 season. The Englishman will start the Miami Grand Prix down in 13th after a tough qualifying session, behind all three of the drivers currently ahead of him in the drivers' championship.
Sergio Perez, who won last time out in Azerbaijan, claimed pole and has a chance to leapfrog Red Bull team-mate Max Verstappen in the overall standings. For Hamilton and team principal Wolff, though, things have gone from bad to worse.
“There is not a lot to say to Lewis because the car is simply not fast enough,” Wolff admitted. “Putting him in a situation on his out lap where the driver is not able to prepare his tyres makes it even worse."
Hamilton's team-mate George Russell will start the race in sixth. However, the team boss said he couldn't take much solace from the 25-year-old's performance given the wider issues affecting the car.
“I take no enjoyment from finishing sixth and it is the lack of comprehension of what is wrong that makes this car such a nasty piece of work," Wolff added. "The car is not a good car.
"There are problems everywhere, with the base performance of the car and the lack of understanding of the car. The performance is just really bad. It is not acceptable.”
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Hamilton insisted the team needed to do better after their struggles in qualifying. After four top-six finishes in the opening four races, he will need to move up the field if he is to secure a repeat.
"That last one, I was the last of the pack and I tried to get temperatures into the tyres but then because I was at the back of the queue at the last corner," the Englishman told Sky Sports. "I just lost all temperature in the tyres. I couldn't do the lap."
"When you're fast, you can sit back and be more relaxed. You can go at the last minute and take your time. You know it's likely you're easily going to make it into Q3.
"We know that it was very hard and there was a 50/50 chance we would get into Q3 so we need to be better with our timing. But anyway, it's done. I'll just try to get my head down tomorrow and see what I can do from 13th."
Wolff had earlier warned Hamilton that planned upgrades might not bring an immediate upturn in fortunes for Mercedes. The hope is that the improvements will be in place in time for the San Marino Grand Prix, on the weekend of May 19-21.
