Red Devils had initially wanted to land the central defender next summer.
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Premier League champions Manchester United may have to bring forward plans to sign highly rated Benfica defender Ezequiel Garay after Serie A high-flyers Napoli also entered the race to land the Argentinian, according to reports in the Daily Star.
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The Red Devils have been keeping close tabs on the 27-year-old for the past 12 months and have even sent scouts out to watch Garay in action first hand in the Portuguese capital.
However, it was initially thought that United would wait until the end of this current campaign before making their move for the Argentina international, with new head coach David Moyes viewing the central defender as the long-term replacement for veteran Englishman Rio Ferdinand at the back at the Theatre of Dreams.
But with Rafa Benitez now understood to also been keen on signing Garay, but when the winter transfer window opens again for business in the new year though, the Scot may be forced to accelerate his plans to land the player and instead go head to head with the Spaniard at the turn of the year.
Either way, though, Garay will not come cheap, with the buyout clause in his contract worth a reported £17 million.