A move was agreed for Fulham defender Chris Smalling in January 2010 but the deal did not go through until the end of the campaign with the centre-back staying at Craven Cottage in the meantime.
As for players who've long since left United, Louis Saha was a big-money capture in 2004 after impressing for Fulham in the first half of the season while another striker, Henrik Larsson, joined on a short-term loan from Helsingborg to increase the attacking options in 2007.
While it sounds unlikely that Sir Alex will add to his January buys list in 2013, he did caveat his recent declaration with, "You can never say never in football because you don’t know who might become available." In the meantime, the rumour mill remains in overdrive as usual.
2012: Frederic Veseli (Man City)
2011: Anders Lindegaard (Aalesund)
2010: Chris Smalling (Fulham)*
2009: Ritchie De Laet (Stoke), Zoran Tosic (Partizan Belgrade)
2008: Manucho (Petro Atletico)
2007: Henrik Larsson (Helsingborgs, loan), Dong Fangzhuo (Dalian Shide)**
2006: Nemanja Vidic (Spartak Moscow), Patrice Evra (Monaco)
2004: Louis Saha (Fulham)
* = Stayed with Fulham until end of season.
** = Loaned to Royal Antwerp as did not have work permit.