Red Devils boss Jose Mourinho is determined to land another defender in the Janaury transfer window but has been told a deal must be put on hold as the Portuguese outfit remain in the Champions League.
The 22-year-old Sweden international is also able to operate from right-back and has started in 12 of Benfica's 13 Primeira Liga games, and all six of their European fixtures.
Mourinho has been moitoring Lindelof for some time and is keen to push a move through in the new year, but may turn his attention elsewhere if made to wait