The Armenian midfielder has started just one Premier League game since his move to Old Trafford from Borussia Dortmund and has failed to impress manager Jose Mourinho.
However, Mkhitaryan is confident that he can win over his new manager and believes he should be a key player for the Red Devils.
"I know I can succeed at Manchester United and I want to show everyone that I deserve to be a key player in this team, in this league," he told the Armenian FA.
"There are no disappointments, just challenges; I never stop or give up when I encounter obstacles in my way, I just continue going until I reach my career objectives.
"Today I don’t have enough playing time, so I have to do all my best so the coaching staff gives me the chance to play. I'll keep working hard and this will pay off".