Robert Shwartzman admits his dream of racing in Formula 1 could be over.

This year, the Russian - who kept his motor racing career alive amid the Ukraine conflict by switching to an Israeli license - has been the full-time reserve driver at Ferrari.

But the 23-year-old says the way the 2023 grid vacancies filled up ahead of next season is the starkest sign yet that he will not be able to realise his dream.

"This season was really difficult," Shwartzman is quoted by Ilta Sanomat newspaper.

"Unfortunately I didn't drive anywhere, which is a huge disappointment for a racing driver. I don't know what's going to happen yet, but it's really hard to get into F1."

According to the Finnish newspaper, one of the last straws for Shwartzman - the 2021 Formula 2 runner-up - was seeing Logan Sargeant secure the Williams seat for next year.

Sargeant is related to American oil billionaire Harry Sargeant III.

"Will my dream come true or not? I do not know," admitted Shwartzman. "I can guess that probably not, which is sad because I've worked so hard.

"F1 is a bit strange these days," he added. "I don't always really understand how the teams make their driver solutions.

"I don't want to name names, but I think places are not always allocated based on skills."