The fans favourite pulled up after just 24 minutes of the 1-1 draw at Leeds on April 5, and damaged the same hamstring that ruled him out for three months after he limped off at Fulham in September.
Head coach Jimmy Floyd Hasselbaink told www.qpr.co.uk: “Jamie is out for the season now unfortunately. “He needs an operation, which he will have today.”
Mackie has suffered the slings and arrows of football fortune since he returned to the club last summer.
After the Fulham pain that went with a 4-0 thumping on the night , the 30-year-old returned to the side in January, but has made only 16 appearances in total, scoring just the once in the 3-2 defeat to Middlesbrough on April 1.
QPR without Mackie head for Brighton this evening hoping to put right the west London wrongs of the Fulham 5-0 thumping by the high-flying Seagulls on Friday.
Hasselbaink will bring back Junior Hoilett for starters following the 0-0 draw at Cardiff on Saturday, and promises other changes as well.]
Read what Brighton boss Chris Hughton says about the Rangers threat.