Claire Williams
Claire Williams (R) convinced Felipe Massa to postpone his retirement so as to replace Mercedes bound Valtteri Bottas Getty

Claire Williams had made it clear when talks began with Mercedes regarding the transfer of Valtteri Bottas that it will only happen if it is beneficial to the Williams Formula One team.

The Finn was appointed Nico Rosberg's replacement by the reigning champions earlier in the month, but according to the Grove-based team's deputy principal, it came with a 'little bit of pain' as they had to make a compromise on the commercial front to get the deal over the line.

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Mercedes supply engines to Williams and it is likely that they would have lowered their costs in order to tempt them to part with Bottas, despite them having confirmed their driver lineup for the forthcoming campaign prior to the end of the 2016 season. Williams was forced to convince Felipe Massa to make a u-turn on his decision to retire at the end of the 2016 campaign, as they were adamant they needed an experienced head to guide young rookie Lance Stroll in 2017.

"When you've made your driver line-up and you've put plans in place around that pairing, that's a really difficult position for any team," Williams told Sky Sports News. "Of course you're going to make it work for you otherwise you wouldn't agreed to it.

"We've put in some good commercial terms to make Mercedes feel a little bit of pain," the Williams deputy principal added.

The team's deputy chief has also dismissed doubts about Massa's motivation owing to his decision to retire from the sport at the end of the previous campaign. Williams is confident that the Brazilian will deliver the same level of competitiveness as he has done thus far in his F1 career.

"We are never going to put a driver in the car who we don't believe can deliver. As everyone saw even in his last race last year [in Abu Dhabi], he delivered for this team," Williams told Sky Sports in a separate interview.

"He has lost none of his motivation. I know there's a lot of talk out there 'let the guy retire, leave him alone' - he wants to come back. Little-known to me, I didn't actually realise that he didn't really want to retire and so I think Felipe is going to do a good job this year," she added.