Williams technical boss Paddy Lowe has insisted there are "no doubts" over Robert Kubica's return to Formula One to drive for his side next season.
It was announced last week that Kubica would be returning to Formula One and driving for Williams next season, replacing Sergey Sirotkin.
His new team-mate George Russell has insisted he can work well with Kubica in 2019, in the 20-year-old's debut season.
"Williams is a very open team," the F2 world champion explained at the post-race test in Abu Dhabi. "Here we don't have Russell's team and Kubica's team; it's one team."
Russell had his first chance to drive in the 2018 Williams car, which was also the slowest car on the grid.
"I had positive impressions," Russell revealed. "The team works in a similar way to Mercedes and Force India, with whom I have worked. For my first morning with Williams, it was great."
As for Kubica, Lowe has insisted there are "no doubts" despite picking Sirotkin over the Pole a year ago.
"We went through a careful evaluation process last year and chose Sergey and it was a good decision," Lowe explained. "Robert was then unable to show his best side. But 12 months later we know him better, we have seen what he can give us and what he can do.
"Perhaps people outside the team still have doubts, but no one in the team even thinks about it."