3. Rio Ferdinand
Few central defenders throughout history have been as assured and composed on the ball as Rio Ferdinand.
The current Manchester United defender, who also played for West Ham and Leeds United, has tremendous technique - and this is just one of the reasons why the Red Devils made him the most expensive defender in history back in July 2002.
The England international is now in the autumn of his career, but can Manchester United afford to lose both him and Nemanja Vidic in the same summer?