Sauber is keeping its options open for 2018 on the power unit front, with both Honda and Mercedes currently under consideration as suppliers.
FIA sporting regulations stipulate that manufacturers have to notify the governing body by May 6 which teams they wish to supply next year, so Sauber's negotiations are likely to ramp up in the coming weeks.
It was reported earlier this week that the Swiss outfit could be viable candidate for Honda power, and even perhaps pick up a baton which McLaren - Honda's works customer - appears all too willing to drop.
Team boss Monisha Kaltenborn has confirmed that preliminary talks have indeed been held with the Japanese manufacturer.
"All I can tell you is yes we have had discussions with them," Kaltenborn told Motorsport.com.
"But we are open on our engine situation. I think we have a couple of options. We know that a call has to be made soon.
"We know that, and of course the sooner you have clarity, the better for development."
Mercedes would obviously have Sauber's preference as an engine supplier, but it remains to be seen whether the Hinwill-based outfit could afford the German power unit.
"It's also a possibility," added Kaltenborn.
"Like I said, we have a couple of options, and we are simply not decided."
Sauber could perhaps benefit from the presence in its team of works-supported and Mercedes protégé Pascal Wehrlein, and profit from a partly subsidized deal similar to the one Manor enjoyed last season.
Should McLaren part ways prematurely with Honda (a contractual termination difficult to achieve however) and enter into an agreement with Mercedes for 2018, it remains to be seen if the manufacture could also supply Sauber given the extension of its resources.
Regardless of any future deal, it's unlikely Sauber will extend into next season its current agreement with Ferrari.
GALLERY: F1 drivers' wives and girlfriends
Keep up to date with all the F1 news via Facebook and Twitter
