Canadian Stroll has arrived home to Montreal warning his fans that he cannot deliver a good result in this weekend's grand prix.
"The car is just not competitive," he said.
"We are working on all of the parts to improve the package and be able to fight for the points again, but it takes time.
"I am doing everything I can to improve the car and I intend to continue working this way all season long."
Stroll, still just 19, has taken flak in the press this year, not just because of his 'pay driver' status but because of his attitude amid Williams's crisis.
However, Claire Williams has backed the young Canadian.
"He has worked very hard to improve the points he had to improve," she said.
"He's under a lot of pressure, getting criticism that is not deserved and I think he's showing tremendous maturity in dealing with all of it.
"I am very proud of the work he has done for us and I hope that we will soon be able to give him a car that will allow him to show his full potential. I honestly believe he has a great career ahead of him in F1."
It sounds as though Williams, arguably relying on the millions brought not only by Stroll's father Lawrence but also teammate Sergey Sirotkin, is not shopping around for a new driver.
Williams said of Stroll: "We're not talking about a contract yet, but we think Lance has lived up to our expectations so far and we do not like to separate from drivers without good reason."
The team will at least get a boost in Canada in the form of Mercedes's new-specification engine.
"In principle we could benefit from the engine, but I prefer to wait until we're on track to say," Stroll warned.
"So far this season we have sometimes progressed and sometimes regressed, so I just hope the next step will be positive."
Williams is currently bottom of the team rankings with four points so far this season.