City are offering around £16 million plus Ireland in exchange for Milner, a package Villa have agreed to, but Ireland has reportedly demanded a £2million pay-off from cash-rich City to play his part in the transfer.
City are believed to be unwilling to adhere to those terms, meaning Ireland remains the last frustrating stumbling block in the ambitious Manchester club's chase for one of their top summer targets. If the move fails, Ireland could see himself not included in City's 25-man squad list, meaning he won't be able to play in the Premier League this season.
City manager Mancini has told Ireland, who has played for the club for his entire senior career, the time has come for him to move on to pastures new.
"Stephen Ireland is a good player but he has been here all his life and he needs to change,'' said Mancini. "Sometimes it can happen that a player stays with the same squad for 15 years and plays well but a moment arrives when he needs to change. Now is time for him. I really think he can improve.''
Rather than pay Ireland £2million to leave, City would be more likely to up their transfer offer and buy Milner in a straightforward purchase. But Mancini said he is confident the transfer will go through as originally planned once Ireland considers his options over the weekend.
"We need two or three more days with this situation,'' said the Italian. "It is right that everything goes well for everybody but I am confident it will be OK.''