Mkhitaryan was a regular starter for the first few months of the season, finding the net during the 4-0 win over Everton and the 4-1 Champions League victory at CSKA Moscow.
The 28-year-old has had a fair share of highs and lows since last year's big-money switch from Borussia Dortmund, with the attacking midfielder now going through a challenging period.
That drop-off led Mourinho to omit him from the last two matchday squads and the Portuguese wants a reaction as he prepares to bring the Armenian back into the fold in Saturday's Premier League clash against Brighton. "I'm not speaking about one or two, I'm speaking about three, four or five".
'That was enough because the others, they work to have a chance, everybody works to have a chance. He started the season very well and after that step by step he was disappearing. Everybody works to have a chance.
Many United fan's were hopeful that after a season of settling in time, this season would see Mkhitaryan hit the type of form he produced for Dortmund in the 2015/2106 season, which saw him notch nearly 50 goals and assists for Dortmund and ultimately earned him his big-money move to Old Trafford.
And Mourinho believes that despite trailing only neighbours City in the Premier League goalscoring charts, his players are not scoring enough, with French global Martial singled out as an example of a player who has responded well to being left out. The Armenian had registered 11 goals and 15 assists in the 2015/16 Bundesliga season and was clearly a huge talent.
"I think we had an improvement with (Anthony) Martial". "The last couple of matches Mkhitaryan was out and other players had the opportunity to play that normally Mkhitaryan has". However, much like in his early days at Dortmund it seems the player is once again struggling with the mental demands of playing for a top-club.