Stoffel Vandoorne has said that if he does not race for McLaren next year, he could go elsewhere in the pitlane.
The 24-year-old Belgian and reigning GP2 champion has been strongly backed by the British team, and made his grand prix debut for McLaren early in 2016 when Fernando Alonso was injured.
Yet the Woking team have yet to declare their 2017 driver lineup, amid speculation that McLaren will replace Jenson Button with hotly-rated reserve driver Vandoorne.
At an event ahead of his home Belgian Grand Prix, Vandoorne warned that he actually might not be a McLaren driver next year.
"My contract expires at the end of 2016," he told La Derniere Heure, a French-language Belgian newspaper.
"So I'm in a fairly comfortable position. If they cannot guarantee me a ride in F1 for 2017, I can go elsewhere."
Asked if that 'elsewhere' might be the works Renault team, Vandoorne answered: "Yes, or elsewhere. There are still other free seats, but I can't tell you anything more.
"The only thing I can confirm is that I have to drive in F1 next season. And I hope with all my heart that it will be at McLaren."
McLaren are currently seventh in the constructors' championship.