GEELONG midfielder Allen Christensen could miss up to half the season after having back surgery.
The 22-year-old had the operation on Friday after suffering recent back and leg pain associated with a lumbar disc injury.
The Cats revealed late on Friday that Christensen won't be able to resume training for around 12 weeks, and from there he'll have to work to regain match fitness.
"Obviously this is a blow to Allen and our team in the short term, but the surgery should ensure the issue is resolved and he will be able to move and play more freely," Geelong football manager Neil Balme told geelongcats.com.au.
"We have experience with this type of surgery, with Dawson Simpson having the same operation two years ago.
"Allen is a key player but we have confidence that we have depth and this will provide an opportunity for someone to step up.”
Christensen's absence follows recent surgery to Cats skipper Joel Selwood, forward Steven Motlop and emerging talent George Burbury.
Burbury had surgery on Thursday after sustaining multiple breaks to his jaw following a sickening clash with Magpie Nick Maxwell in Wednesday night's NAB Challenge opener.
Selwood could be available for Geelong's next NAB Cup game, while Motlop is hopeful of being ready for the start of the home and away season.
Christensen debuted for Geelong in 2011 and has played 57 games.
