Sergey Sirotkin believed it was “quite obvious” that he would have a second season in F1 with Williams only to lose his race seat to Robert Kubica.
Sirotkin joined Williams at the start of this season but failed to shine on the big stage.
In a year when the team struggled for form, the Russian driver managed just one of their seven points.
As such Sirotkin was dropped in favour of the returning Kubica.
He told Motorsport.com: “I would strongly hope for [a second season] and it looked like it was the case.
“It looked quite obvious it would be the case for quite a while. But it’s F1, it’s a difficult world.
“To get success there are also many, many different parameters which unfortunately most of the time aren’t up to the performance of the driver or whatever.”
News of the 23-year-old’s departure came days after his backer SMP Racing decided not to continue their relationship with Williams.
He had, however, hoped it wouldn’t change his situation with the team.
“Last week we had a few meetings, I could understand that discussions are not going the way we want them to be.
“Obviously SMP Racing wanted to be professional and didn’t want to accept those things, it was a strong sign for me that’s it not going to happen.
“But I always hoped that probably something would change, a moment or whatever. It didn’t happen.”