"Thanks for all the concerned messages last night (Saturday). Have had scans and am booked in for surgery on Thursday. Focus my attention to 2014 now," Copley tweeted to his followers.
The young outside back was stretchered off Redcliffe Oval 18 minutes into Brisbane's 16-14 pre-season trial loss to Gold Coast on Saturday night.
Scans on Sunday confirmed he'd ruptured his right patella tendon.
Brisbane's team doctor Peter Hackney feared Copley's season was over after examining him in the dressing rooms.
It's a tough blow for the talented 21-year-old who fought back from a broken leg last season.
He was highly rated by coach Anthony Griffin to fill a backline position following the departure of Kiwi international Gerard Beale to St George Illawarra and uncertainty over the return of representative winger Jharal Yow Yeh from a serious ankle injury suffered early in the 2012 season.
Copley, who has scored 14 tries in 38 NRL games for Brisbane since making his debut as a teenager in 2009, had been looking forward to securing a permanent spot in Griffin's starting side.
He will undergo surgery on Thursday.
While Copley's unfortunate injury is a blow to Brisbane, the club backed a winner last month when it contacted former Broncos flyer Denan Kemp and offered him a flat-rate contract to come home.
Kemp, who was pulling beers in a Wollongong nightclub, jumped at the offer.
He scored a try in Saturday night's trial, showing he'd lost none of his blistering pace or clever footwork that saw him score a record-equalling four tries in a match before leaving the club to play for the Warriors in 2009.