
The Eastlands boss has quickly identified the full-back positions as problem areas for a side that has conceded more goals than any other of the teams battling for a place in Europe.
Ansaldi is rated at £6million by his Russian club and was part of the side that shocked Barcelona at the Nou Camp by beating them in this season's Champions League group stage.
He made his debut for Argentina in a friendly in Spain in November and has a good chance of being named in Diego Maradona's World Cup squad.
The former Newell's Old Boys defender, 23, has been quickly targeted by Mancini as a left-back who can also play on the wing and he will be expected to compete with Wayne Bridge, who has struggled for form and fitness in recent months. The move underlines City's aims to target squad players in this window instead of going for superstar names like Brazilian ace Kaka.
Mancini spoke this week of the problems he would have persuading top players to leave clubs who are still involved in the Champions League.
The Italian believes the current squad is in need of some fine tuning but does not have to be overhauled if they are to make the top four.