The Scotland international has been sidelined since suffering a double leg break in January's FA Cup tie against Blackburn Rovers.
Warnock will not be rushing Mackie but he is delighted to see the forward back on the training field.
"Jamie has been given the go-ahead to return to full training, which is fantastic news," Warnock said.
"He must have called me 14 times last night to tell me that he's fit for Sunday.
"Obviously he won't be available just yet, but it's great to have him back."