The Armenian was cup-tied for Arsenal's recent win over Chelsea in the EFL Cup semi-final second leg, but is in line to feature against Swansea next week.
It remains to be seen how Wenger will use Mkhitaryan, given that he is not the same player as Sanchez who ventured further forwards on the left of the Arsenal attack and was also given free licence to roam across the pitch.
"I've known him for a long time and of course it was not very hard to make this decision to come to Arsenal, because I think the way that Arsenal play [make] it a dream for every player to come here and play offensive football".
"He has usually been a wide player and can absorb the role as a winger, playmaker but he can be a box-to-box player". "I don't rule it out for him to become a box to box player".
He was relegated to a fringe role at Old Trafford by Jose Mourinho and lacks match fitness, but Wenger said he has settled into life at Arsenal well and is in contention to play on Tuesday night. "I have played many times against him for the Czech Republic as well and you could see how good he is".
Wenger, Arsenal's manager since September 1996, added: "I pushed always for football to do more against doping, so I don't see why we should not cooperate".