The Armenian earned the man of the match award for his key role in the 4-1 EFL Cup victory over West Ham, which booked a place in the last-four.
The summer arrival from Borussia Dortmund claimed two assists as Zlatan Ibrahimovic and Anthony Martial bagged a brace each.
Mkhitaryan has struggled to earn much game-time since joining the Old Trafford outfit but after strong outings against West Ham and Feyenoord he looks to be settling in.
The midfielder felt he did well individually but also praised the squad as a whole for blowing away the east London club.
Mkhitaryan said: "I'm excited for the performance, I'm excited for my performance.
"We've done a good job.
"We've tried our best to win because the last game, on Sunday against West Ham, wasn't very good for us when we didn't win.
"But I think this time everything worked out and we're very pleased."