Hargreaves believes blame for this season's problems can be shared around.
He told the Manchester Evening News: "The start of Fellaini's United career hasn't gone as well as he would have wanted it to or as well as Moyes wanted it to. When you pay that kind of money, you expect an impact.
"You know at United, the likes of Keane and Scholes set the standard in midfield and it's been difficult for new players to reach that standard but I don't think you can blame any one individual for all the problems. It's not fair to point out one individual - players all over the park need to improve."