The Red Devils were linked with the Moroccan ace over the summer, but failed to beat the Stadio Olimpico-based outfit to his signature.
Despite him having only been a Roma player for a matter of months, Moyes is believed to be ready to make a fresh move for the 26-year-old, as he looks to bolster his defensive options.
With both Namenja Vidic and Rio Ferdinand having struggled with injury, the Scot is said to have serious concerns regarding the future of his backline.
Benatia is seen as a player who can step straight in and settle the club’s rearguard after an impressive start to the campaign with Roma.
The Italian side paid domestic rivals Udinese £11.3m for the defender during the last window, and are likely to demand a substantially larger fee in January to sanction a sale.
United are also watching Benfica’s Ezequiel Garay and Eliaquim Mangala or Porto.