Germany's Nico Hulkenberg stayed silent on Thursday about reports he has signed a deal to switch to Sauber next year to replace McLaren-bound Mexican Sergio Perez.
"I know there is lots of talk about my future, but at this point I don't want to comment on the speculation," he told reporters before this weekend's Indian Grand Prix.
"I want to focus on this weekend, which is the most important thing."
If Hulkenberg does move to the Swiss team, it remains unclear who his prospective team-mate would be. The list of possible partners includes current Sauber driver Kamui Kobayashi of Japan along with several others.
Kobayashi, who had a podium finish at the Japanese grand prix, said he is working to try and secure the funding needed to stay at Sauber next year. He acknowledged that his chances of securing a drive depend on him finding a sponsor.
"After I came back, after Suzuka and Korea, I wanted to celebrate but there was no time to celebrate. I had to work to get a sponsor," he said.
"It's not something we wanted after Suzuka, but this is the situation.
"Normally for a top team it doesn't matter as they have a big budget, but for the lesser teams they need some budget because it's a different system. This is what I have to understand."
The Japanese driver said he remained focused on this year.
"We need to fight for more championship points and this is key. At the moment I think I need to focus more on this season and then we'll see."
Sauber are 20 points behind Mercedes with four races to go but Kobayashi said he felt his team can still beat their rivals.
"It's difficult to say, but I believe we can do it," he said.
"I don't know what I need to do, but even one or two points are very important, but 20 points in four races is not too bad."