Mackie completed a move to Loftus Road from before the season started, but his second stint with Rangers hasn’t gone according to plan.
The forward has missed much of the season so far after picking up a serious hamstring injury back in September.
And he said: “It’s been one of the most frustrating spells of my career, and I want to have a big impact for the second half of the season.
“As players we need to be counted, and only we can turn it around. We’ve got to stick together as players so we can go on a run.”
Mackie made his comeback as a substitute in QPR’s most recent match against Hull City.
The 30-year-old forward came off the bench late on in that contest, but he was unable to stop his side falling to a 2-1 defeat.
That loss means that QPR have now failed to win any of their last six matches, leaving Jimmy Floyd Hasselbaink still searching for his first victory since taking charge.
The Dutch boss has been unable to inspire his team to three points so far, and the R’s poor sequence of results has seen them slip all the way down to 16th place in the Championship table.