The England Under-19 defender joined the Foxes on loan last week, along with team-mate Jesse Lingard, but picked up a hamstring injury during his debut against Bolton.
After returning to Carrington for treatment, it's hoped that he could be available again soon to City boss Nigel Pearson.
"It would be a good loan move if he had not got injured!" admitted Ferdinand to manutd.com. "It would have been great for him. He is a great prospect. I have spoken highly of him for a couple of years now. He has a really big future. I am just disappointed he has had a setback with a little injury."