The Italian club's president Albano Guaraldi has revealed that the Premier League side's offer for Ramirez is not enough.
The Uruguay international himself claimed earlier this week that a deal has been agreed among all parties and that he was looking forward to joining the Saints.
However, it has now emerged that this is not the case.
"The situation is much more complicated than he thinks," Guaraldi told Sky Sport 24. "It's not just about figures, but seeing what is included and what isn't.
"The offer we received has not been considered suitable. His agent has already reached an agreement with the English club, but we haven't.
"Now the situation is static. We made our demands and will see what happens."
Guaraldi also slammed Ramirez for announcing publicly that he was set to join Southampton without knowing the full details of the negotiations.
"I don't understand why Gaston said those things," he said. "I won't even get into the behaviour of his agent.
"We spoke to the top Italian clubs about Gaston, but I have always been clear: I'd let him go only for a suitable offer, which so far has not arrived. I maintained my consistency and refused the bid.
"I am irritated because one of my players spoke as if he were already at another club, when there still isn't any agreement.
"I can understand his desire to make the move, but I do not share his timing and methods. All negotiations can collapse, which is why I consider the player's attitude to be premature."
Bologna reportedly want £15.7m for Ramirez, while Southampton are prepared to pay £11.8m.