3 players to come in prior to Friday's friendly. That's come from someone (not a player) who would generally know these things. I'm presuming that if the first two are a left back and a centre forward, then the third would either be the "wow" signing, or more likely, Milner or Arteta.
Also, I've been given the impression that once the pre-season friendlies get under way proper on Friday, Mancini does not want to concern himself with anymore players coming in. In terms of players going out - Bellamy, Jo, Neds, and RSC are the nearest/most likely to exit...
So in a nutshell, the word is that all transfer business needs to be complete by the time the squad hits NYC on Saturday..