"I was happy to give him responsibility when I think a lot of people probably didn't think that he wanted it."
McKenzie's policy with Cooper has been in contrast to that of predecessor Robbie Deans who gave up on the skilful No10.
While Deans controversially overlooked Cooper for this year's Lions series, McKenzie also surprised by benching him for his first two tests in charge, preferring Matt Toomua to play against New Zealand.
But since then, the newly-appointed vice-captain has improved with every display to have a major hand in eight of the 13 tries the Wallabies have scored in wins over Italy, Ireland and Scotland.
A big part of the Wallabies' resurgence has been due to his playmaking and match-winning chemistry with Israel Folau.
Cooper put Folau over for a try against Scotland with a perfect inside ball and then combined with the fullback and Stephen Moore for a second to Chris Feauai-Sautia.
McKenzie lauded Cooper's communication skills, rugby IQ and vision.
"I watch him train every day and if a player is out of position, if there's 10 players over there and someone is not there, he knows straight away, well before anyone else, even before I know.
"He's just got great vision."
- AAP