Williams technical director FX Demaison has conceded George Russell will be a "big loss" for the team as he departs to partner Lewis Hamilton at Mercedes.
After three years racing with Williams, Russell will move to pastures new next season with former Red Bull driver Alex Albon replacing him at Grove.
Demaison joined Williams in March and has played an important role in shaping the team's direction for 2022 with a raft of all-new aerodynamic regulations.
For all his knowledge, however, Demaison reflected the loss of Russell's detailed feedback will hurt Williams in its development push.
“For sure, it's a big loss for the team because he knew the team," Demaison said in an interview including GPFans.
"George is somebody who's pushing everybody, every day, every minute, every hour.
“But I think he's a great driver and he deserves to have a great car which we don't have for him at the moment. It's normal for this guy to go somewhere else."
Whilst Russell's switch remained just a rumour, various names were linked with the potential vacancy at Williams.
But with the loss of Russell's feedback, Demaison confirmed, “It's why I was pushing to have an experienced driver for next year or at least with some F1 experience and not having a too young driver because we need this feedback. We're only engineers and at the end, we don't drive a car.
“Even if we believe we do a lot of simulation and we know everything, we are not driving the car. The driver is a big part of the process.
“We believe that with Alex we'll have this experience. He seems to be a quite technically-oriented driver. At the moment, we need his inputs.
"We're looking forward to working with him and benefiting from his experience.”