Mercedes team principal Toto Wolff delivered a brutally downbeat verdict after Saturday's qualifying misery at the Miami Grand Prix - describing the team's W14 car as "a nasty piece of work".
The Silver Arrows are a street behind the mighty Red Bull RB19, and also struggling to get close to Ferrari and Aston Martin as the season prepares for its fifth race in Florida on Sunday evening.
Qualifying on Saturday brought significant pain for the team, with seven-time world champion Lewis suffering the embarrassment of failing to even make it out of Q2. He would qualify in a lowly 13th position.
Things were a little better for George Russell, but he admitted the team was flattered by his P6 showing, with Q3 ending early after a late crash for Ferrari's Charles Leclerc.
Afterwards Wolff went deep on the much-maligned W14, bemoaning the reasons which it is just not delivering the desired results.
“It is the lack of comprehension of what is wrong that makes this car such a nasty piece of work," he said.
"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. It is not acceptable.”