4) Roberto Mancini (Unattached)
A manager who divides opinion, but possibly just the lind of disciplinarian this Arsenal side lacks at the moment as they become something of a soft touch under Wenger. Roberto Mancini has proven success in recent times and led Manchester City to a thrilling Premier League title in in 2011/12, as well as the FA Cup the season before that. Still without a club since leaving Turkish giants Galatasaray.