Robert Kubica says the last 12 months have injected him with belief that he can still race at a high level, despite the difficult 2019 campaign he has endured.
However, it was soon apparent that the Grove-based squad was far away from the rest of the competition on the grid, and was consistently competing at the rear of the field.
On Saturday in Abu Dhabi, Russell completed a 21-0 qualifying victory over Kubica this year. Kubica says that he felt comfortable during the opening practice session on Friday - adding that he thinks the changes were made to his teammate's car earlier in the season.
"I think generally it hasn't been easy for George and myself and for sure, he did a very good job," Kubica said. "I struggled quite a lot many times with losing the feeling in the car.
"This was also the case here. In FP1, it was the best from one area. It was the only session where I felt comfortable this year in the car with one thing.
"It took a lot of races but it looks like the team is now on top of it. I had the opportunity to test it on Friday, it was probably used in the past with George. It doesn't matter really."
Kubica is set to retain a test and development role in Formula 1 next year, while he is also being lined up for a full-time race seat in DTM.
Despite his difficult year, Kubica says his return to F1 after nine years on the sidelines informs him that he is still able to compete at the highest levels in motorsport.
"In the end, when you are having such a difficult year, it changes very little if you are P18 or P20," Kubica said. "What counts is what is your personal feeling of what you did and what you could do better.
"It's difficult to look at it now because the season has been pretty negative. We are race drivers, you always want to get better results. So I think all this season has also been very difficult to judge where my personal performance could be, and where it is.
"But on the other hand, this season - and I think this is most important - it gave me belief that I can race on a high level in another championship.
"That's why my mind is on racing again next year because I think working with the team, whatever I will be doing, I can still have fun and I can still deliver. This is the most valuable outcome of this season.
Bahrain International Circuit - Winter testing