The Premier League champions are yet to make a signing this summer, in stark contrast to their lavish spending over the last two years which has seen them lift the FA Cup and their long wait for a top flight league title.
Arsenal's contract rebel Robin van Persie has been continually linked with a move from the Emirates to Eastlands over the summer, following in the footsteps of former Gunners Samir Nasri, Gael Clichy, Kolo Toure and Emmanuel Adebayor.
Mancini refuses to be drawn on names but the Italian has revealed he is working on bringing some new faces to the club and expects business to be done over the next couple of weeks.
He told Sky Sports News: "We did well last year. This year will be harder because when you win, the problem is to win again.
"For this reason I think that we need to improve our team with maybe some new players,
"I'm sure that maybe in the next two weeks we can do something about new players.
"We are talking to some players, but the market is not easy. It's difficult, and for this reason we need more time."
The 47-year-old is only expected to add one or two players to his squad which already boasts a wealth of talent in almost every position.
Mancini added: "I don't know at this moment. But we have a lot of players and I don't think that we need 10 new players."