On Sunday Goal.com revealed that Manchester United could be tempted to cash in on star centre-back Nemanja Vidic amid interest from mega-rich Russian club Anzhi Makhachkala.
Any potential sale would represent a huge gamble by Sir Alex Ferguson but Vidic is now 30 years old and the sort of offer Anzhi might submit could prove difficult to resist.
Despite the presence of young defenders such as Phil Jones and Chris Smalling, Ferguson would surely be tempted into the transfer market to replace one of the pillars of the team that won the Champions League in 2008.
If the 70-year-old wished to shop within the division, he could look to move for Arsenal defender Thomas Vermaelen. The Gunners would be reluctant to lose their captain, but have not been able to resist the overtures of rival clubs in recent years and might be at risk if they do not soon mount a serious challenge for the Premier League title.
Elsewhere, youngsters such as Torino's Angelo Ogbonna or Nordsjaelland's Jores Okore are likely to be in demand among Europe's top clubs soon. Ogbonna has previously been linked to United while Okore was recommended to Ferguson by club legend Peter Schmeichel.
Mats Hummels of Borussia Dortmund could provide a more established, top-tier option, but is likely to command a significant fee. The Germany international has shone as part of Jurgen Klopp's two-time Bundesliga-winning side but could be persuaded by the idea of pursuing a new challenge in the English top flight.
A longer shot, meanwhile, might be former United player Gerard Pique. The Spaniard has emerged as one of the world's best centre-backs at Barcelona but reported internal difficulties made last season his least enjoyable at Camp Nou. That uncertainty could be cured by the change in manager in Catalonia, but if problems persist Ferguson could take advantage of the opportunity to bring the world champion back to Old Trafford.
Which player should United chase if Vidic was to make a shock departure? Do they require a seasoned performer such as Vermaelen, Hummels or Pique? Or would another young star such as Ogbonna or Okore represent the way foward for Ferguson? Have your say by voting in our poll and leaving your comments below. You can also get in touch via Facebook and Twitter.