The Argentinian has been regularly linked with a switch to Old Trafford, however now it appears as though the move could be about to happen.
The Mirror claim that Manchester United are in pole position to sign the defender, who has one year left on his current deal with Benfica.
The 27-year-old has spent three seasons in Portugal since signing from Real Madrid, and has attracted interest from the likes of Manchester City and Zenit St. Petersburg.
However according to the Mirror, Manchester United are confident of getting their man and start their summer spending in earnest.
Boss David Moyes is said to have been handed a sizeable transfer kitty for the summer as he bids to revive the Red Devils following the retirement of Sir Alex Ferguson last year.
Garay is said to have a release clause worth £20 million in his contract, although Manchester United are unlikely to pay that much given that he is only 12 months away from being a free agent.
The news couldn't come at a better time for Manchester United fans following their 3-0 defeat against rivals Manchester City which means they cannot avoid accumulating their worst points tally in the Premier League era.
Moyes has been charged with overhauling his playing squad, with Nemanja Vidic on his way out already and the likes of Patrice Evra and Rio Ferdinand likely to follow.
However he has endured a difficult time in charge to date, and his side are currently in 7th place in the Premier League.