Deschamps attributed his decision to the 21-year-old's lack of playing time at United this season.
He said: "Even though Anthony is playing a little bit more since Zlatan's injury, he has a limited amount of playing time. He's been doing some good things but he's not as decisive as he was before.
"The two things are linked. Perhaps he's lost a bit of confidence, a bit of rhythm. He has the quality, the potential, as Anthony showed last season.
"But it's normal to have a dip – he had a very packed season last year.
"There's been a change of coach, maybe a different system as well. You know it can happen to more experienced players, but for young players, it happens practically all the time.
"There has been a little bit of a dip, a lack of confidence. It can take a bit of time."