9) William Carvalho (Sporting Lisbon)
One of the best young midfielders in Europe, William Carvalho was linked strongly with a move to Arsenal for much of the summer transfer window, though it is reported that the Gunners never managed to meet Sporting Lisbon’s valuation of the player. The 22-year-old would certainly have made an upgrade on the likes of Mathieu Flamini and Jack Wilshere in the deep-lying midfield role, and a superb long-term replacement for club captain Mikel Arteta, who is also out injured at the moment, leaving Arsenal short of quality options in that part of the pitch.