De Gea is expected to return to the starting XI for today's blockbuster against Chelsea.
"There's obviously an agenda on De Gea," Ferguson told manutd.com. "We've experienced that in the press for some reason. They seem desperate for the boy to fail.
"That's the impression I get and I don't understand it. It's nothing to do with his age. They never did that with Petr Cech.
"I think they will all want interviews with him when he's doing well. He doesn't speak English, was looking for a house but has got one now, and is learning to drive in England. He's 20 years of age and doesn't know the culture of the country. I think that's a lot to deal with but he's shown great composure about the whole thing. He's not got himself flapping about the goalmouth. I think he's absolutely outstanding - the boy is tremendous."