Pastor Maldonado says there are no guarantees that he will stay at Williams next year.
The Venezuelan had been thought to be guaranteed to stay at the outfit in 2013 thanks to his close ties to team sponsor PDVSA - whose deal could be worth as much as £30.8 million next year.
But despite having previously stated that Williams was his first option for the future, Maldonado said in Japan that he was now less clear about his future plans.
"I don't want to talk about that now," he explained. "The team is still looking for the next year, for the drivers, so I prefer to not answer your question about the drivers.
"But for sure there is still a market, it is moving a lot, so I hope to be in the best place I can."
He added: "Williams is a bit early to talk about. We are always waiting until the end of the season and we are fully focused on the championship. We are fighting the championship with Force India. We are doing all of our best to be ahead of them."
Maldonado's options for a competitive drive elsewhere appear quite limited, with Sauber the only realistic alternative if he is looking to move.
The Swiss outfit, which is looking for a replacement for Sergio Perez, has been most strongly linked with Felipe Massa, Jaime Alguersuari and Esteban Gutierrez in recent days however.
Maldonado's uncertainty about his future may also be fuelled by the fact that an election is taking place in Venezuela this weekend – which could have an impact on the PDVSA F1 sponsorship.
Under the terms of its Williams tie-up, the oil company must pay its sponsorship by October 31 of the preceding year.