The implication of remarks by an IMF official is that it is very unlikely to provide funds at the first stage.
The fund could however join in later, provided both the eurozone and Athens take steps to address IMF concerns.
The problem for the IMF is that its staff believe the elements so far agreed are not enough to make the Greek government's debt sustainable.
Negotiations are underway and the IMF is involved. But its staff think the eurozone governments need to give Greece debt relief.
That does not have to be in the form of explicit reductions in the outstanding debt. It could mean longer repayment terms and delays before any payments are required - so called grace periods.
The eurozone has insisted that it is only prepared to look at the possibility after Greece has made a start on implementing whatever conditions will be agreed.
The IMF official also said Greece needs to commit itself to further reforms if it is to make the debt situation sustainable.
He didn't spell out what they were. But they will involve reforms to the government finances to control spending and maintain tax revenue. They will also cover what are called structural reforms, to remove barriers to economic growth. Faster growth would generate more tax revenue to help make the debt situation sustainable.
Neither Greece nor the eurozone are ready to take those steps, the official suggested.
The implication then is that Greece and the eurozone will find it very hard to persuade the IMF to stump up any cash at the start, though it might be wiling to do so if there is debt relief and further reform later.
The immediate significance of the IMF's position is political.
If the bailout talks do produce an agreement to provide financial assistance from the eurozone bailout agency, the European Stability Mechanism (ESM), it will still need approval by some parliaments, including Germany's Bundestag.
Many members including some from Chancellor Angela Merkel's own party, are very unhappy about a third bailout for Greece. There is a much better chance of persuading them to acquiesce if the IMF is on board.
Financially, the IMF is less critical. It is the eurozone that has provided the great bulk of the resources for the first two bailouts and would do so with the third.
It could afford to find the full expected €86bn (£60bn) if really necessary. The ESM has the capacity to make €455 billion of new loans at present.
The political roadblock erected by the IMF is more difficult.
