Stoffel Vandoorne says McLaren have yet to explain why he has been dropped from their driver line-up for 2019 and recognises his chances of finding a seat in F1 next season are slim.
The Belgian has partnered Fernando Alonso for the past two years, but McLaren will have two new drivers next year in the form of Carlos Sainz Jr and rookie Briton Lando Norris.
Vandoorne has been regularly outperformed by veteran Alonso, who is to leave F1 at the end of the season.
But he still expected to have been told McLaren's reasoning by team boss Zak Brown.
"Obviously it was the team's decision, and I have to respect the decision," he told reporters at the Singapore Grand Prix.
"But there hasn't been a clear explanation why. I think that's a question for them to see their exact strategy for the future.
"It would be nice to know. But I think there's not much to explain."
With many teams finalising their drivers for next season, Vandoorne concedes his chances of staying in F1 next season are diminishing but he remains optimistic of earning a drive.
"Obviously I know exactly where I stand, my position for next year. At the moment there's nothing decided for next year, probably similar situation to Esteban [Ocon] let's say," he added.
"The driver market has been strange for a couple of weeks know and things are moving. Seats are closing down almost every day.
"The chances to be on the F1 grid next year are very slim, but until everything is fixed I guess you've got to keep talking, keep trying, and give everything for it. That's the only thing I can do at the moment.
"We are exploring some different series as well, which hopefully in the next couple of weeks I will know something more about.
"Until the Formula One door is closed, you've got to keep all the options open. There's some interesting projects that could become a possibility for next year but at the moment nothing is done, still a free agent let's say."
