Nemanja Vidic
Vidic's contract expire at the end of the season.Reuters

Spanish giant Barcelona are considering signing Nemanja Vidic when the defender's contract with Manchester United expires at the end of the season after his agent claimed that he is unlikely to sign a new deal.

Barcelona have been looking for a centre-back since the summer when they failed to sign Thiago Silva and with 35-year-old Carlos Puyol no longer at his best.

Former Liverpool player Javier Mascherano is currently partnering Gerard Pique in the defence despite being a midfielder while young Marc Bartra has struggled to convince manager Gerardo Martino that he deserves a place in the starting line-up

The Catalans have recently been linked with David Luiz but Spanish newspaper Mundo Deportivo claim the club are considering signing Vidic as they could bring him to the Nou Camp for free next summer.

Mundo Deportivo report that Vidic has been monitored by Barcelona in recent years and that his good relationship with Pique, who played with him at United, could be a key factor in signing him.

Manchester United are planning to enter discussions over extending Vidic's stay at Old Trafford for at least one year, but his agent, Silvano Martina, claimed recently that he is open to move away and bring an end to his time at United.

"At the moment, I would rule out an extension with Manchester United.
 Vidic, given his contract situation, has several teams looking at him," Martina said.

"Vidic is a very good player and will have no trouble finding a new club. For the time being we are remaining calm. At the moment there has been no contact (with Napoli) but they are one of the best clubs in Europe."

Vidic's departure would be a huge blow for manager David Moyes as his partner Rio Ferdinand also faces an uncertain future at Old Trafford with the club yet to offer the former England international a new contract either.

United are already looking at possible replacements and in the last few weeks they have been linked with Real Sociedad youngster Iñigo Martinez and Porto´s defender Eliaquim Mangala.