City are reported to be on the lookout for a midfielder with Ivory Coast star Yaya Toure set to depart Eastlands on African Cup of Nations duty.
However Mancini is adamant that any new arrivals will be dictated by whether the club is able to negotiate the departures of players such as Carlos Tevez, Nedum Onuoha and Wayne Bridge.
Tevez, who has not played for City since his bust-up with Mancini during the Champions League match against Bayern Munich in September, has been linked to a move with AC Milan with other clubs also interested in the striker.
"We need to sell three or four players and with Carlos we could close (a deal) with a club in the next three or four days, and also possibly Wayne. Then maybe we can do something," Mancini said.
"We hope for us and for Carlos we can do a deal. There are two or three teams in Italy, a team in France, and another team involved - I hope for him he can start to play football.
"We could maybe bring someone in, but we need to sell."
Although Tevez appears likely to leave, Mancini does not believe he needs to replace the striker in his squad, confident he has enough firepower left with Mario Balotelli, Edin Dzeko and Sergio Aguero backed up by attacking midfielders Samir Nasri, David Silva and Adam Johnson.
Mancini admitted he is also interested in Roma midfielder Daniele De Rossi but doubted whether the Italian would be available.
"De Rossi is a top player, like Yaya, but he plays for Roma, a top team, and he was born there. I don't know if he will leave," he said.