Williams chief technical officer Paddy Lowe says he saw a clear improvement in Lance Stroll in 2018 that suggests the Canadian entered Formula 1 too early in his career.

Stroll was the reigning European Formula 3 champion when he made the step up to race for Williams in 2017 at the age of 18, following in Max Verstappen’s footsteps and skipping Formula 2. Lowe believes Stroll would have been better off with another year of development before stepping up to F1, saying the progress over the past 12 months was clear to see within the team.

“Starting with Lance, his second year in Formula 1, my personal view is that in hindsight he came into Formula 1 too early,” Lowe told RACER. “There are a number of reasons for that, but I think he would have been better to come a year later when he was better prepared.

“It was a really, really tough year for him last year but we have seen him make a real step change over the winter. He’s been much stronger this year, particularly in his qualifying which was a difficult part for him last year. But he’s completely transformed his approach to qualifying this year and that’s played out well for him. And then becoming more confident as a driver, therefore getting some better results from that.”

Lowe says Sergey Sirotkin — who made his debut with Williams this year at the age of 22 following three years in GP2 and F2 — is an example of a driver who had enjoyed better preparation for F1.

“In Sergey’s case, a rookie but a rookie who was ready for Formula 1. Very, very committed. Trained and worked incredibly hard and a really great team player. Always the team and what the team needed uppermost in his mind.

“He’s been a really important component of what we’ve been doing this year through what were very difficult times. He’s always been very practical and level-headed about everything, even at the worst moments, and that goes a long way in a team that’s struggling.”

Stroll will race alongside Sergio Perez at the Racing Point team in 2019, while Sirotkin has been left without a seat after Williams selected Robert Kubica and George Russell as next year’s race drivers.