The 21-year-old, valued at €15m (£12m), looked set to pick the Saints despite interest from Internazionale, Liverpool and Tottenham Hotspur.
“The negotiations with Southampton are at a standstill because they haven’t given us the financial guarantees we asked for and so we’ve put things on hold,” he told Sky Sport 24.
“Our relationship with them remains a friendly one but both parties has conflicting demands.
“Last year Ramirez was getting a bit restless and I promised that this year he would be sold, at a certain price.
“This year no such offer has arrived, the conditions have not been met. We carried on with negotiations regardless but we couldn’t reach an agreement.
“At the moment we’re trying to resolve the situation, but the two parties can’t agree so the discomfort and nervousness is understandable.”
Guaraldi revealed the 21-year-old, who scored eight goals in 32 appearances last season, is threatening to not play for the club again ahead of the new Serie A season which starts on Saturday.
But the Bologna president added if the club’s financial terms are met, then Ramírez will be allowed to leave.
“He’s very angry, Ramirez has told me that he’s threatening not to play any more,” Guaraldi said.
“I’ve tried talking to him, to explain the situation, that I can’t sell him without guarantees.
“Footballers are often badly advised and in this case his agent has made moves without our knowledge.
He added: “There has been no concrete proposal to date, there has been some contact from abroad, but we aren’t prepared to let him go for less than a certain figure.
“If the conditions that we laid out at the start of the transfer window are met, the player will be sold, otherwise we wait.”
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