McKenzie suffered a groin at training and will now miss the next three to four weeks.
But the club is taking a cautious approach with him and will not rush him back.
Defender James Strauss is now in doubt for Friday’s NAB Challenge clash against Hawthorn at Aurora Stadium in Launceston, after hurting his hamstring last Saturday.
Strauss suffered the injury during last Saturday’s NAB Challenge loss to Brisbane Lions at Visy Park.
Rookie Tom McNamara has also been added to the injury list after suffering a foot problem. He will miss three to four weeks.
As expected, key Demons James Frawley (shoulder) and Cale Morton (hand) remain sidelined for at least another month.
And premiership ruckman Robbie Campbell (achilles) is still another six to eight weeks away from resuming.
First-year Demon Troy Davis (thyroid disorder) will miss a further six weeks.
Jack Fitzpatrick (foot) could miss another month, while Michael Newton (hand) will be out for three more weeks.
Melbourne injury list
Troy Davis (thyroid disorder) - 6 weeks
Jack Fitzpatrick (foot) - 3-4 weeks
James Frawley (shoulder) - 4 weeks
Jordie McKenzie (groin) - 3-4 weeks
Tom McNamara (foot) - 3-4 weeks
Cale Morton (hand) - 4-5 weeks
Michael Newton (hand) - 3 weeks
James Strauss (hamstring) - test