Manchester City chief Ferran Soriano admits they can't sit on the sidelines during this summer's transfer market.

The Observer says he has privately acknowledged that the club made serious errors of judgment last summer when Brian Marwood was in charge of recruitment.

Soriano, who was not at the club at the time, believes Mancini has genuine grievances after they lost out on Robin van Persie to United, as well as other targets including Eden Hazard and Oscar, and ended up with Javi García, Maicon, Jack Rodwell and Scott Sinclair.

The former Barcelona executive expects to sign three or four established players and has spoken behind the scenes about the importance of each of them being an upgrade on players currently in those positions. He has also confirmed there will be a considerable exodus of Mancini's fringe players.