Since TJ13 broke the news yesterday that Williams will be announcing next week that Russian Sergey Sirotkin to partner young Canadian Lance Stroll, further news unfolds as to why Kubica lost out.

Polish sports website SportoweFakty have reported that BBC’s Andrew Benson has had insight from Williams as to the reasons why they’ve opted for Sirotkin. Benson eluded that Sirotkin was a likely candidate for Williams in his BBC column last week. Below is a direct transcript from the Polish news publication from yesterday.

“The team staff revealed to me that the results achieved on the track are primarily for the contracting of Sirotkin over Kubica. The tests in Abu Dhabi, which took place after the final race of the previous season, turned out to be crucial in this matter.”

“The main issue for Robert was primarily the speed on “qualifying” laps, during which the car has a small amount of fuel in the tank. Kubica, on all his runs using the tyres could not significantly improve performance.”

“I also received information that the 33-year-old himself revealed to his manager of his problems with adapting to the new tyres provided by Pirelli. There is nothing strange about this. Many regular F1 drivers complain about the revolutionary tires of the Italian company. For Kubica, however, the adaptation process can be a much more difficult challenge. Unlike the rest of the drivers, the Pole has not driven any of the last six seasons since Pirelli became F1’s partner.”

“In the end, Williams management in Grove decided that Kubica couldn’t get the job done and that in their current situation there is no room for risk. Hence the choice of Sirotkin.”

“On the first day of testing, the team message was simple: Sirotkin has money, but Kubica is a clear favourite and if nothing negative happens. Kubica will be in the Williams seat next season.”

“Unfortunately, as already mentioned, some significant barriers have been emphasised and now we will probably never see Kubica return to Formula One.”