Robert Kubica has questioned why Williams would make the decision to remove his new front wing between Friday and Sunday at the Japanese Grand Prix, especially after he told them it was the best his car had felt in a long time.
Both Kubica and George Russell had outings with the new wing on the first practice on Friday, while the former was allowed to keep it for FP2 also. However, for qualifying and the GP, it was removed and replaced with the old spec - a decision which he says “crossed boundaries”.
"Friday was very good," Kubica told a Polish television channel at Suzuka.
"First time for a very long time.
"We changed the front wing. It wasn't supposed to be better and on the second car it did not give any advantage or was even worse. But my car felt a lot better.
"However, for strange reasons, the wing was taken from my car this morning before qualifying. I think there was just too much time to think about it on Saturday...
"The typhoon passed, but I think the decision was not related to the track here, but more so to other reasons or choices.
"This morning, however, gave me a lot to think about. I knew some things, but this morning some boundaries were probably crossed."
This incident comes after the Russian GP which saw Williams make the decision to retire Kubica from the race - not because of any car issues, but so they could save parts for future races.
The Pole was hoping that, after that, Williams would act more favourably towards him, but in the end he was left disappointed again.
"I was hoping after the really disappointing Russia we would be here trying to do our best and this is what we tried to do on Friday," Kubica admitted.
"Actually on Friday I ended up with quite good feelings but my feelings were probably too good.
"Conditions were different but on Friday something happened which gave me quite a lot of confidence and improved my feeling in the car.
"We agreed on something and then on Sunday morning things changed for whatever reason.
"I think it was not a decision of people who are here.
"I don't want to go into the details too much but after Russia where we were disappointed overall when you have a driver who says 'for the first time for a very long time I can drive the car properly and I'm actually properly exploring the car', this is what every team would look to have.
"But for whatever reason..."
Kubica ended up crashing in qualifying, forcing him to start the race from the pitlane.