Fernandes has made a quick impact since joining United in January, and is being compared to some of their greatest ever midfielders.
And he says that his job would be a lot easier if he had those two covering for him from deeper positions.
Asked in a Q&A with fans, Fernandes could not choose between who was better, Keane or Scholes.
He said: "This is a difficult one, eh? I think the most difficult until now.
"So, I don't know. If I can have both, better, because I need the guy behind me kicking everyone and recovering balls, like Roy Keane does, and have the quality to give the balls to the guys up front.
"If you look at Roy Keane, he's the kind of player all teams need. Teams play in different ways, but all the teams can have him.
"Doesn't matter if you play in possession, in counter, you need a guy like this normally.
"I think Roy Keane is an excellent player and he can give me a lot of cover in the back. To play side to side with Scholes would be fantastic.
"If I can play with both, I play with Roy Keane in the back behind me and Scholes. Because me and Scholes can both go in the area scoring.
"We want to score, we want to be in the area, no? And maybe we will need Roy Keane at our backs."