United paid Shakhtar Donetsk £52 million for the Brazil worldwide, but he has only started six Premier League matches.
The Red Devils managed to battle to a 2-2 draw with top-four contenders Arsenal at Old Trafford on Wednesday night to avoid a second defeat in three Premier League games.
Nearly everyone, including the United faithful, had their money on an Arsenal win but a late error by Sead Kolasinac allowed the home side to level the score for the second time as the game ended 2-2 at the full-time whistle.
The manager then elected to use Herrera and Nemanja Matic in front of a five-man defence against Arsenal, with Pogba and Fellaini relegated to the bench.
"Of course, Lindelof and Alexis, we don't even speak about them, but we need answers and for sure we are going to play with players not at the maximum of their potential, but players that will make themselves available like Smalling and Jones did".
"There is a big difference in class [between Manchester United and the Premier League top two] but it wasn't this game [against Arsenal] that showed us that, we knew that coming into this game because Liverpool and [Manchester] City, I think, are a cut above the rest in this league", Ferdinand told BT Sport on Wednesday night. Manchester United will take on Fulham, while Crystal Palace travel across London to face West Ham United (all at 7pm). They have good players in their side. "They are led by one of the two most important managers in the history of the Premier League, so they have the potential to come here tomorrow and to give us a very hard match".