Real Madrid are understood to be reluctant to meet Di Maria's €40 million release clause in Portugal and have suggested including one of their players used in a rotation system.
Garay, Royston Drenthe, Mahamadou Diarra and Fernando Gago are all likely candidates to be used as bargaining chip by Madrid in their efforts to sign Di Maria.
It had been suggested that Drenthe held Benfica's preference, but fresh reports in the country claim the Eagles have set their sights on Garay.
The 23-year-old, who signed for Madrid in 2008, emerged as a starter at the Santiago Bernabeu last season after Pepe sustained a serious knee injury.
However, with the Portugal international fit to play again and Madrid boss Jose Mourinho in the market for some fresh blood for his backline, the chances are that Garay will be deemed surplus to requirements.
Earlier today it was reported that Real Madrid and Benfica had reached an agreement in principle for Di Maria, with one of the few pending things looking to be which Madrid player will move in the opposite direction.
The arrival of Garay at the Estadio da Luz could well pave the way for the departure of highly-rated David Luiz, who has garnered interest from across Europe.
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