Greater Western Sydney midfielder Dom Tyson will be out of action until well into next AFL season after rupturing a knee ligament.
The 19-year-old will have surgery next Tuesday to repair the posterior cruciate ligament he injured at training on Wednesday.
He is expected to be ready to play again in May, with the 2013 season starting in March.
Giants sports science manager John Quinn said the club had consulted several surgeons before deciding how to treat the injury.
"It was an unfortunate incident caused by a collision with another player as part of a tackling drill," Quinn said.
"There is slight damage to the medial ligament but fortunately the ACL is intact and there doesn't seem to be too much collateral damage.
"We looked at all options and determined this was the best course of action.
"The recovery time from an operation like this is around five months and it is expected that Dom could be back playing in May."