Mkhitaryan has struggled for first-team action since his £26m switch to Old Trafford from Borussia Dortmund in the summer.
The Armenian international has not featured since his one and only start in United’s league defeat to Man City on September 10.
Injuries have played a part in the 27-year-old’s absence, and Mourinho recently claimed that Mkhitaryan needs to prove his fitness before returning to the team.
According to Manchester Evening News reporter Rob Dawson, Mkhitaryan prepared with the rest of the team this morning and has a chance of making the squad.
The former Shakhtar Donetsk player was one of four new faces, including Zlatan Ibrahimovic , Eric Bailly and Paul Pogba, signed by Mourinho in the summer.