"He's in a team with these two guys playing absolutely phenomenal so for Carrick and for Ander, it's just patience".
While the duo were crucial to the United challenge last season, Mourinho has preferred alternative midfield options as his side have made a flying start to this campaign, yet he had these words of encouragement for Carrick and Herrera ahead of the Carabao Cup tie against Burton Albion at Old Trafford on Wednesday.
"I knew he was a player with a lot to give, but I think the relation between the players and the managers are very important in their performance levels, confidence levels and self-esteem levels".
"That's life in big clubs".
His current contract is set expire at the end of this season by which time the midfielder will have turned thirty and the club have a policy of offering players of that age one year rolling deals though Fellaini is likely to want a longer stay.
"My team mates make me a better player and I think I make them better players".
"(Sergio) Romero played the Europa League final, which was the game of the season for us and he is not playing", the United boss said. "We can not play with [only] 11 guys".
"They are going to be important players for us, for sure".
The United boss singled out Herrera for praise following his late introduction on Sunday from the bench which calmed things down and eventually saw the Red Devils run out comfortable 4-0 winners over Everton.
But he warned his squad not to take the challenge of a Championship club lightly, telling them that they will lose if they do not play "seriously". "We take it seriously". I know how lucky I am to play for Manchester United.
"Our squad is good but we don't have 30 players, we have what we have and a couple of injuries now with (Paul) Pogba and (Axel) Tuanzebe".