The Armenia international has been left out of the squad for eight of the last nine games in all competitions.
However, the Red Devils face Championship outfit Bristol City in the League Cup quarterfinals and the 28-year-old could play a part.
"He can. I am making a few changes for the match, not many, because Bristol is one of the best teams in the Championship and for me now the Championship is not the Championship of five or 10 years ago," Mourinho was quoted as saying by Sky Sports News.
"The Championship is now high-quality teams with lots of players that could be playing in the Premier League easily. So we need to take the game really seriously. But I am going to make a few changes and it's possible Mhiki is involved.
"At the moment we are playing (Juan) Mata, (Marcus) Rashford, (Jesse) Lingard or (Anthony) Martial, (Romelu) Lukaku and the bench has been Ibra and one of the other ones - Martial or Rashford.
"There is no space for everybody because you need balance on the bench too."