Despite arriving at Old Trafford in a big-money deal from Borussia Dortmund, Mkhitaryan has almost been non-existent in the Premier League, having not featured since September.
Last year's Bundesliga Player of the Year has only played once since the derby defeat to Manchester City, coming off the bench in the Europa League loss to Fenerbahce earlier in November.
And as Mkhitaryan's ongoing struggles continue, Mourinho claims the 1-1 draw with Arsenal on Saturday would have been too much for him to cope as he looks set to be given an opportunity in the reverse Europa League fixture against Feyenoord on Thursday.
"I told him, 'This [Arsenal] was not the game for you, I don't think you need 10 or 20 minutes from the bench, I think you need a good game and you need to either start or if not to come [on] for the second half'," Mourinho said.
"He needs less pressure and better conditions for him to express his qualities.
"Yes [he is getting closer]. I told him today that he is going to be involved in the game against Feyenoord. He is trying.
"Obviously he is not happy but he is transforming his frustration in a good way, which is [to] close the mouth and work hard and try to adapt."