The tactical work followed the homework with Sir Alex admitting United have watched Cluj's "last two or three games."
"As part of our preparations we have to assess the opposition and we saw their performance in the last game against Braga," said Sir Alex. "[Before that] they knocked out Basel, beating them twice. We know from our own experience last season that Basel knocked us out. That gives us every respect for Cluj because it tells you they’re a good team.
"Cluj defend quickly and get plenty of bodies behind the ball. The main strength is counter-attack, as they showed against Braga.
"Counter-attacking has become a very important part of European football. Now it’s done by four or five players, not one or two like 20 years ago, and the positive nature of the counter attack has made the Champions League much better."