The Tynecastle club had asked for a partial lifting of the signing ban imposed by the SPFL following their descent into administration last summer.
As part of his argument for leniency, Bryan Jackson of administrators BDO, cited health and safety concerns over the club's young players.
The Gorgie club were also hit by a Scottish Football Association embargo which prevents them signing players aged over 21 until February, although that sanction is academic given their continuing insolvency event.
After the SPFL board meeting at Hampden, Doncaster said: "The board did not discuss the Hearts situation at all today.
"The situation is that late last Friday, the administrators at Hearts put forward a broad request for us to consider allowing the registration of a particular player.
"The rules are quite clear as to what the board can and cannot do.
"They can consider applications for individual players to be registered but to consider those applications they do need to see a copy of the player's contract and make it clear which player they are replacing.
"We haven't had that and the board don't have the flexibility to over-ride that rule.
"That rule enabled Hearts to bring in Danny Wilson last January and last summer 10 players were registered on the basis of one-in, one-out at Hearts.
"In some quarters it has been portrayed as an appeal against a decision but there is no appeal.
"In fact, there is no decision by the board. It is a general rule that effects all clubs in administration that prohibits them from signing new players other than bringing forward individual requests for players to be brought in on a one-in, one-out basis and if we get such an application, we can consider it at that point.
"There is a huge sympathy for Hearts players, supporters and indeed the administrators for the position they find themselves in.
"It is not their fault that they are in their position at the moment, but the rules are very clear."