Smith injured his knee during the opening half of the GC SUNS 32-point victory over the Western Bulldogs at Metricon Stadium on Saturday night.
General Manager - Football Operations, Marcus Ashcroft confirmed the results.
"Unfortunately the scans have shown that Zac will require reconstructive surgery to his right knee.
Zac and the club's medical team will meet with the surgeon to determine when he will undergo surgery."
Ashcroft confirmed Smith will be sidelined for a considerable period of time.
"The nature of the injury means Zac will miss the rest of the 2013 season and will be in rehabilitation mode when the 2014 pre-season commences."
Smith, 23, has played 44 games with the GC SUNS since making his debut in the club’s inaugural match against Carlton in round 2 at the Gabba in 2011.
