Jose Mourinho says if Luke Shaw wants to get back into the squad at United, he must work hard as Mkhitaryan did.
The 21-year-old defender will not be playing in the second keg Europa League match against Saint-Etienne.
Luke Shaw has only made 14 appearances for Manchester United this season in all competitions.
And Mourinho said the left-back would be given nothing without earning it.
“He stayed behind in Manchester because I’m playing with Daley Blind, with Marcos Rojo, with Matteo Darmian, and all of them are playing the way I like a full-back to play,” he said.
“Luke has to wait for his chance and work better and better, knowing I give nothing for free.
“When I give something to the players, it’s expensive for them – it’s not cheap.
“They have to work hard every day, they have to play well, so he has to wait. And, at this moment, he’s behind the others.”
Mourinho said Shaw could use team-mate Mkhitaryan as an example in his bid to break into the United side.
“Potentially, he [Shaw] has many things that I like but one thing is potentially, another thing is on the pitch to express all the qualities that I like a player to express,” Mourinho said.
“And he has to keep working, like Mkhitaryan did for a long time.”