In the past, Nemanja Vidic's expiring contract might not have been viewed as a major issue at Old Trafford, with Manchester United's veterans regularly allowed to enter the final months of their deals before signing extensions.
However, the player's agent, Silvano Martina, was recently reported by The Guardian's Jamie Jackson as having spoken on Napoli's Radio Crc, where he revealed his client isn't likely to renew with the Red Devils:
Vidic, given his contract situation, has several teams looking at him. Vidic is a very good player and will have no trouble finding a new club. For the time being we are remaining calm. However, at the moment, I would rule out an extension with Manchester United.
David Moyes will be hopeful that this is little more than an agent's ploy to haggle for a better deal on the centre-back's behalf, but United must now plan for Vidic's exit.
With a summer departure now in sight for the defender, who can sign a pre-contract agreement elsewhere, we look at some of those candidates who would be capable of replacing such an iconic figure in the United squad.
A player long linked under Sir Alex Ferguson's reign at Old Trafford may yet come back into the picture this year, as Ezequiel Garay has come close to a move in the past.
The Daily Mail Online's John Drayton reported the Argentinian saying in October that Moyes wasn't as keen on his services as Ferguson, but Jeremy Cross and Paul Brown of the Daily Star have since claimed that the defender is in the Red Devils' sights.
Garay isn't the same aerial predator that Vidic is; his strengths lay closer to the ground where he can use his deceptive amount of pace at his disposal to great advantage.
Cross and Brown state that the defender has a £17 million release clause in his contract, which wouldn't be out of reach at this stage, and Benfica's financial issues may lend a hand in loosening the Portuguese giants' grip somewhat.
One of the cheaper acquisitions that United could hope to make in 2014 is that of Basel utility Fabian Schar, who has stepped up to the plate with his performances for the Swiss champions this season.
Like Vidic, the 22-year-old has a knack for scoring goals and netted three times in his first two appearances for the Swiss national team, grabbing five goals for Basel so far this season, per Transfermarkt.co.uk.
One disadvantage of Schar's purchase would be that, like Phil Jones and Chris Smalling, the player is still relatively inexperienced and would leave Jonny Evans as the most seasoned member of United's back line come next season—unless Rio Ferdinand extends his career.
Eliaquim Mangala is being tipped for a bright future after the French international rose to prominence in Porto's defensive line last season, forming a solid partnership alongside Nicolas Otamendi.
Mangala's performances have continued to impress this term, too, with the Dragons keeping clean sheets in five of the 11 Primeira Liga matches in which Mangala has played.
The 22-year-old's strength is arguably his most attractive quality, with the Express' James Dickenson reporting that the former Standard Liege starlet is a priority for Moyes this January.
Oliver Kay of The Times says there is no chance of the move coming to fruition this winter, however:
The Daily Mail (h/t ESPN) claims a fee of £40 million would be required in order for the centre-back to be named as Vidic's successor.
Mangala's physique is freakish for a man of his age, with Squawka showing that the defender won 70 percent of all tackles and half of all headed duels in the Champions League this season.
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