Having pulled out of the sport amid the global financial crisis in late 2008, it is expected Honda is preparing a return for 2015 for the new turbo V6 rules.
"I think we've all heard the stories that Honda are coming in and there are other people looking at joining formula one," Mercedes team boss Ross Brawn said.
"I think it (the V6 rules have) regenerated that area, which it needed."
Honda is expected to team up for a works engine deal with McLaren, while Sauber has been linked with a customer supply of Japanese power.
Toyota, meanwhile, withdrew from F1 a year after Honda, at the end of 2009.
Swiss newspaper Blick's veteran correspondent Roger Benoit said in Bahrain: "Yes, even Toyota is toying with a comeback.
"The Japanese have Williams in sight, and they could get Japanese favorite Kamui Kobayashi back in a race cockpit."