Haas is still staying quiet on the identity of its 2019 driver lineup.
With next year's grid now taking shape, neither of the American team's current drivers have been confirmed.
But every indication is that Kevin Magnussen and Romain Grosjean are staying.
Denmark's BT newspaper reports that Haas' contract 'option' on Magnussen expires on 1 October - the day after the Russian grand prix.
When asked if Haas is therefore planning an announcement for this weekend at Sochi, a team spokesman answered: "Nothing (is planned) yet."
Magnussen also declined to comment.
But he said in Singapore: "I'm just enjoying the best time I've had in Formula 1."
