The Armenian arrived at Old Trafford with a big reputation in 2016, but struggled to hold down a place in the first team and quickly found himself deemed surplus to requirements by manager Jose Mourinho.
However, Mkhitaryan completed a swap deal to Arsenal during the January transfer window and marked his home debut with a hat-trick of assists in the 5-1 win over Everton last weekend, and he is eager to look to the future now rather than dwelling on his United stint.
"I don't want to find excuses. I don't want to blame anyone...I am starting a new chapter in my life, in my football career and I am very happy to be here," he is quoted as saying by Sky Sports News.
"I will be pleased to achieve more than I have done in Manchester, of course. I don't have anything to prove to anyone. I just have to enjoy myself, do my best and at the end I will see where I can reach."
Mkhitaryan is expected to get his first taste of a North London derby when Arsenal take on Tottenham Hotspur at Wembley this weekend.