The Armenian is expected to be recalled to the matchday squad for Saturday’s Premier League game with Brighton after being out of contention altogether for the past two games.
Mkhitaryan last started for United, and turned in a lacklustre display, in the defeat against Chelsea at the start of the month and, Mourinho explained, that was the final straw for the manager.
“I was not happy with his last performances,” said Mourinho. “And I am not talking about one or two. I am talking about three, four or five. He started this season very well and after that, step by step, he was disappearing.
“His performance level — in terms of goalscoring, assists, high pressing, receiving the ball high up the pitch, bringing the team with him as a number 10 — were decreasing step by step.
“And there was a time that was enough. The others, they work to have a chance. Everybody works to have a chance so it’s as simple as that.”
Mkhitaryan has endured a torrid time at Old Trafford since his arrival in a £26 million ($35 million, 29 million euros) deal from Borussia Dortmund in 2016.
He found himself banished from Mourinho’s league line-up for well over two months early last season after a dismal display in their 2-1 derby defeat to City.
But he appeared to have won over his biggest critic — Mourinho — with some impressive performances as United won the Europa League and clinched Champions League football.
– Forwards left out –
Mkhitaryan has not been the only creative or attacking player to come in for criticism from the United manager, with Juan Mata, Anthony Martial, Jesse Lingard and others left out at various times due to dips in form.
And Mourinho believes that despite trailing only neighbours City in the Premier League goalscoring charts, his players are not scoring enough, with French international Martial singled out as an example of a player who has responded well to being left out.
“The team that excites me is the team that, after five chances, is winning 4-0,” he said. “That’s the team that excites me.
“I think we had an improvement with Martial, scoring more goals than last season, that is why he’s playing more minutes.”
Ultimately, the United manager also believes that the healthy size of his squad, and the competition for places, is good news even if it means he will face questions about players being left out.
“All positions are open,” he said. “The last couple of matches Mkhitaryan was out and other players had the opportunity to play that normally Mkhitaryan has.”
“There are only 11 plus seven (substitutes),” he added. “When you have a chance and the performance is not what I expect, it’s normal. You have to perform.”
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