Wenger admitted that the club had lost another world-class talent in Sanchez, but is confident that Mkhitaryan's arrival will help to make up for the Chilean's departure.
"I believe we lose a world-class player and gain a world-class player. Overall I think Mkhitaryan has the qualities to integrate into our game. He has a good team attitude as well. I'm confident it will work," he told reporters at a press conference.
"He can play in all kinds of positions. He is very versatile and it should help us going forward. I have no doubt about his attitude. He suffered a bit with the competition he had at United. That his challenge and my challenge to get that out here.
"[His position] depends on the team's performance and his performance in training as well. I'm confident it will work. He can play in all types of positions and through the middle as well."
Mkhitaryan will not be able to make his Arsenal debut during Wednesday night's EFL Cup semi-final second leg with Chelsea as he is cup-tied.