Until now, F1's longest-serving veteran has refused to call time on his grand prix career, despite switching to Indycar for 2012 after losing his Williams race seat.
The Brazilian, 40, made his first visit to a F1 paddock since retiring last weekend in Austin, sparking rumours he was chasing the cockpit vacancy at Force India.
But he told Germany's Auto Motor und Sport: "I don't know whether I'll be driving Indycar next year. Certainly not with my old KV team.
"Everybody wants money. In formula one my chances (of returning) are practically zero."