Ferrari racing director Laurent Mekies believes the bumps at the Circuit of the Americas are worse now than in 2019 by "quite a large" margin.
The track surface was shaved two years ago due to the aggressive bumps formed at the United States Grand Prix venue due to the subsidence of the underlying soil at the facility.
With the process repeated ahead of this year's running after complaints from MotoGP riders at the start of the month, hopes were high the bumps would be less aggressive than in previous runnings.
Mekies has suggested, however, the surface is worse than in 2019 which has led to a tense experience so far, although Charles Leclerc and Carlos Sainz start fourth and fifth following a strong qualifying performance.
"I think everybody started on the back foot, with the bumps, certainly we did, with the high level of bumps on the track," assessed Mekies.
"It was certainly making life for the drivers more difficult than what we would have hoped and therefore we worked through the day to see if we could restore some of the confidence that they were losing in these more difficult conditions.
"I think it is worse than 2019, by quite a large bit. Here, there has always been attention given to the bumps because there has always been a lot of work to be done on the track to keep it as flat as possible.
"It was quite a lot more difficult but nothing that will stop the car from running, it is just a new challenge we will have to deal with."
Leclerc and Sainz "responded in style" in qualifying
Despite the difficulties experienced throughout practice, Leclerc and Sainz managed to overcome them in qualifying to give Ferrari the best possible result behind a top three of Red Bull duo Max Verstappen and Sergio Perez sandwiching Mercedes' Lewis Hamilton.
Looking ahead to the race, Mekies added: "We knew that, on paper, the characteristics of this track were not the best for our package, especially compared to our closest rivals.
"On top of that, it was not easy to find the right settings on such a bumpy track, especially as the drivers need to feel confident in the car to give their best, although that goes for everyone.
"All of us together worked a lot on this aspect, trying out various solutions. In the end, I think we succeeded in giving Charles and Carlos what they needed to get the most out of the SF21 and they responded in style throughout all of qualifying.
"We can expect the race to be very tough on the drivers and the cars with very high temperatures expected, which will have an effect on tyre management, as the track surface is in any case very abrasive.
"Choosing the right strategy and executing it properly will be key. As usual, we will be giving it our all."