5. Filipe Luis
One of the positions United have looked short for cover on in recent seasons has been left-back. Patrice Evra can't carry on forever and whilst Alexander Buttner was brought in recently as a stand-by replacement, The Red Devil's really need proven quality in a position that has leaked so many goals this season. Luis is positionally aware - one of the things Evra certainly is not - and knows how to track back and make a well-timed tackle, too. These are all qualities that would provide United with a bit more steel at the back. But for the sensational form of Radamel Falcao, the Brazilian would have been Atletico Madrid's player of the season last season, and such is the faith invested in him at Atletico, he recently signed a new five-year contract. Even so, that shouldn't deter Ferguson, and he is certainly a player worth inquiring in at least.