The 20-year-old, who moved to United permanently in the summer, has not played in a competitive fixture for the Red Devils so far this season.
While Zaha's former club Crystal Palace were keen to take him back on loan, Moyes has insisted that the England Under-21 international is wanted for the campaign.
"Wilf is one of the boys we have not been able to have a look at so far," the Daily Mail quotes Moyes as saying. "We always said we wanted him in.
"We needed him to see exactly what the level is like and the boy is doing well, but Premier League games are important. We have to win them. So while there will be some players who get the opportunities sooner rather than later, some will have to wait their time because it is a fact you can only play 11."
United are due to take on West Bromwich Albion tomorrow.