Felipe Massa and Valtteri Bottas have been "instrumental" to the Williams squad's Formula 1 revival, according to deputy team principal Claire Williams.
Massa joined Williams this year after eight seasons racing for Ferrari, while Bottas has emerged as a regular podium finisher following his rookie season at Williams in 2013.
Williams is delighted with the contribution that the pair has made.
"They have been instrumental," Williams told AUTOSPORT.
"When we appointed Felipe last year, it was a clear marker that we are very serious as when you bring in a driver of that calibre with that experience, it sends out a message.
"He has been hugely important to the team and developing the car, and galvanising everyone as well.
"That complements Valtteri real well as he's now fifth in the championship, delivering some fantastic races and demonstrating how consistent his racecraft is.
"He has done an outstanding job for us this year, both drivers have, and we are really pleased with the line-up that we have got."
Head of vehicle performance Rob Smedley has also praised the pair for their dedication to the cause of the team, which has helped it to emerge as a threat for a finish in the top three in the constructors' championship.
"It's absolutely central to have we do, having two drivers who are very much onboard and know they are on a journey with us," said Smedley.
"It is really important to have two drivers that put the team above their personal ambitions, and both of them do.
"It's also important to have two drivers that work together and that is working really well at the moment because they need to keep pushing the team in the right direction.
"There is coherence between the two and they are pretty good in their consistency with feedback and the performance we are adding is always in the direction they need."