On Sunday Newcastle simply could not get the ball off United as the four of Michael Carrick at the base, Tom Cleverley on the left point, Shinji Kagawa the right and Wayne Rooney at the top interchanged short passes.
And United boss Fergie said: "We took a gamble because Newcastle are so big up front and they're good crossers of the ball.
"But the football we played from the central midfield positions through Cleverley, Kagawa, Rooney and Carrick was terrific.
"People look at the name Cluj and say they expect United to win but they are a decent side.
"And because we played so well I thought we should find out how far we can go with that diamond system."