The 25-year-old, who has one cap for Spain, would be a direct replacement for Nigel de Jong who joined AC Milan on a three-year deal for £5million today.
It is rumoured that City will pay £16million up front and an additional £2.5million in add-ons for Garcia, who can also play in defence, despite the Portuguese club initially holding out for £24million.
Manchester City boss Mancini said this morning that the club are getting close to several signings – and Richard Wright, Scott Sinclair and Maicon have already joined.
Fiorentina defender Matija Nastasic is also strongly tipped to make the move to the Ethiad.
Garcia came through the ranks at Real Madrid but made only a handful of first-team appearances before joining Benfica for £5.5million three years ago.