Sebastien Buemi has admitted his career will probably stay on its current course in 2014.
Daniel Ricciardo has been signed by Red Bull’s champion team for at least three years, and the other energy drink-owned F1 squad, Toro Rosso, looks likely to field Jean-Eric Vergne alongside rookie Antonio Felix da Costa next season.
It means that if former Toro Rosso driver and current Red Bull reserve Buemi, the 24-year-old Swiss, wants to return to the grid, he will have to do so at a non-Red Bull team.
"The doors are still open," he told Brazil’s Totalrace, "but nowadays it is very difficult because of the financial situation.
"It is not easy when they (teams) are looking for (drivers with) money."
For the last couple of years, Buemi has split his time between serving as the Red Bull reserve at grands prix, and racing for Toyota in endurance sports cars.
He said: "My goal is to return to formula one, obviously.
"But I am very happy to be here," said Buemi, referring to Toyota, with whom he finished second in this year’s fabled 24 hour Le Mans race.
"It’s a great car, we are in a big fight, and I’m doing my best to succeed here.
"I am happy with the situation here at Toyota and what I’m doing with Red Bull, so why not go on like this for another year?" said Buemi.