Duff and Phelps, the club's administrators, published the Company Voluntary Arrangement (CVA) on Tuesday but even if that is rejected by Rangers' creditors, it appears that the Green-led consortium will take over by buying the club's assets.
RFFF committee member Andy Kerr told Press Association Sport: "There are key questions to be asked about finances and investors and there is a direct correlation between the answers to those questions and season tickets."
He added: "Without assurances and confidence, it will be difficult for us to throw our weight behind asking people to pay their £500 or whatever for season tickets.
"I don't know where the money is coming from to fund the next few months. I know there is some money to tide us over but not how much.
"We are worried it might be no different to 12 months ago when the club was bought with borrowed money (by Craig Whyte). On the face of it, it appears no different.
"It all comes back to the same thing. Who are these people who are investing and why? Do they exist? It's time to get the cards in the table."
Green's consortium, which he originally claimed numbered 20 was down to a handful at the last count, two of whom were named as Malaysian hotelier Jude Allen, also known as Javed Abdullah, and Middle Eastern lawyer Mazen Houssami.
Green has pledged £8.5million but the CVA document revealed that £8.3million of that is a loan to be repaid back with interest by 2020.
In the short term, there is uncertainty around how the club are going to find the money to pay players when they revert to full wages on Friday, having taken cuts of up to 75% since March.