The reason Sergey Sirokin lost his seat at Williams to Robert Kubica was rooted in a financial disagreement between the team and the Russian's sponsor says SMP representative Mika Salo.
Sirotkin secured his drive with the Grove-based outfit at the end of last year thanks to SMP's support, with Salo working as an advisor for the Russian financial group's motorsport affiliate.
Following the news that Williams had opted to sign Kubica for 2019, SMP revealed that it had been the one that had initiated the split with the British outfit, declaring itself "unpleasantly surprised by the team's level of performance" in 2018.
According to Salo, SMP was willing to remain onboard with its protégé for next year under the condition that Williams reduce its financial requirements.
"It was pretty much up to Williams," Salo told Finnish broadcaster MTV.
"Of course we wanted to lower the price a bit and get an assurance that Williams will get better. We did not reach a consensus.
"That’s one of the reasons why I’m not worried that Sergey leaves."
The Russian driver's programme for 2019 remains unclear, but Salo suggests a return to the World Endurance Championship is a strong possibility.
"Sergey did a good season," Salo added. "He did a good job and the team liked him.
"His technical knowledge is astonishing and we have LMP cars that need a driver of Sergey’s level."
Dismissing Sirotkin and SMP's backing likely won't have much of an effect on Williams, with the team rumored to be taking in even more money from Kubica's sponsor, Polish energy company PKN Orlen, whose brand will prominently figure on next year's FW42 cars.