Matt Buntine is out for the season with an ACL injury

GREATER Western Sydney has been dealt another injury blow with defender Matt Buntine ruled out for the season due to an ACL tear that he may have been playing with for years.

Bunting walked off the training track with a slight niggle, but scans revealed he had a partially torn ACL, which was a pre-existing injury.

The 23-year-old will undergo a full conventional knee reconstruction next week.

It caps off a disastrous week for the premiership fancies after veteran midfielder Ryan Griffen and young gun Will Setterfield were both ruled out for 10 weeks with ankle injuries.

"After feeling some discomfort at training on Wednesday, Matt underwent scans to initially investigate what was thought to be a meniscus injury, but these scans revealed a partially torn ACL that appears to be a pre-existing injury," Giants general manager of football Wayne Campbell said.

"This is obviously quite a rare set of circumstances, given there has been no cause to investigate any injury in relation to Matt's knee before this and it appears he's been playing with it for a number of years.

"This is obviously devastating news for Matt and we will now map out the best rehabilitation course for him to return to his best.

"Matt is a person of great integrity and character and has the full support of the entire club during this challenging time."

Buntine played the first two games of this year to bring his career total to 41 from his six years at the club.